Cave Story/Enemies

These are the enemies you encounter throughout the game. They are divided up depending on what area you first find them in. Enemies that have slight variations in them (Like say the black and red bat) will be found in the category of which you first encountered one of them (so black and red bat would be in Start Cave).

Bat
The earlier bats are largely useless as they fly in up-and-down patterns only. Grasstown and Plantation bats however use "dive bombing" techniques along with flying in somewhat unpredictable patterns. Red bats are found only in the final cave and in one of the last boss battles. While they don't do the dive bombing tactic, they fly in unpredictable patterns and are faster than the average bat.
 * Damage: 1-2 HP
 * Health: 1 HP
 * Found In: Start Cave, Grasstown, Plantation, Balcony

Critter
More or less the most common enemy in the game, these guys shouldn't give you too much trouble. Be wary of the flying versions later on. Once again, the red versions of the critter are only found in the final cave, but they do not fly so just pick them off from afar.
 * Damage: 1-6 HP
 * Health: 2-6 HP
 * Found In:Start Cave, Egg Corridor, Grasstown, Labyrinth, Plantation

Beware of the purple versions, though, which are in the Labyrinth. They can shoot purple bubbles at you while flying.

Pignon
These guys should give you no trouble at all. They do not actively seek you out so the only way you will get hurt by them is if you accidentally run into one of them. They are only found in the graveyard section of the Mimiga Village.
 * Damage: 1 HP
 * Health: 2 HP
 * Found In: Mimiga Graveyard

Grave Keeper
Watch out for this guy! The grave keeper will walk towards you and strike with his knife, causing quite a lot of damage to your character. Luckily you cannot be hurt by just walking into him. His knife blocks damage, so you can damage him by shooting him in the face when he raises his knife to swing, shooting him on the head when is knife is lowered, or shooting him in the back (regardless of the position of the knife).
 * Damage: 10 HP
 * Health: 20 HP
 * Found In: Mimiga Graveyard

Giant Pignon
The giant pignon is basically the exact same as the normal pignon. It will not actively seek you out so the only way to get hurt is by running into it. The only real noticeable difference is that when shot, the giant pignon tends to "bounce" around a lot more than the normal one, so be careful of that. The giant pignon is found only in the graveyard section of the Mimiga Village.
 * Damage: 1 HP
 * Health: 12 HP
 * Found In: Mimiga Graveyard

Chin Fish
Quite possibly the easiest enemy in the whole game. The chin fish (there is only one) does absolutely nothing but float; it doesn't even bother to move. To kill it, just shoot it however you want, it doesn't matter. The chin fish is only found in the reservoir section of the Mimiga Village.
 * Damage: 1 HP
 * Health: 2 HP
 * Found In: Mimiga Reservoir

Egg Corridor
You'll revisit the Egg Corridor once to meet Sue, and again to visit Kazuma.

Basil

 * Damage: 100 HP (Instant Death)
 * HP: Unlimited

This guy is NOT killable. If you fall onto the bottom and touch him, he WILL kill you instantly.

Behemoth

 * Damage: 2 HP
 * HP: 8

A quite small elephant type. It is possible to stand on top of it without taking damage from it. When four HP is down, he will go berserk, so be aware of that.

Beetles

 * Damage: 2 HP
 * HP: 4 HP

There are two kinds of beetles. One follows you wherever you go. The other just flies back and forth.

If you are invincible, you can jump on bettles to ride them. This may help some speedrun tactics, such as jumping on one during the first cutscene in the Egg Corridor.

Basu

 * Damage: 4
 * HP: 16 HP

A slightly bigger version of the beetles. Unlike them, he can shoot energy balls at you. You can shoot them to prevent damage. When you visit the egg corridor for the second time they shoot two energy balls at you.

Dragon Zombie

 * Damage: 10 HP
 * HP: 54 HP

Dragons from the egg that had an error when hatched. Their fire can be destroyed with one hit but does 10 damage so don't go up close. The best weapon to use is a fully charged spur it will take them down in one hit.

Counter Bomb

 * Damage:
 * Explosion: 30 HP
 * Touch: 1 HP
 * HP: ~ 130 HP

This enemy basically self destructs. Anything in its range will be damaged as well.

Power Critter

 * Damage: 2 HP / 12 HP when landing upon
 * Health: 16 HP
 * Found In: Grasstown

These guys are just moderately harder than their smaller critter cousins. They only come in the flying variety. While they really aren't threatening, watch out for when they fly over you, because you will sometimes not be able to destroy them before they come down due to the increased health. They deal a staggering 12 damage if they hit you on the way down or land on you, so watch yourself.

Jelly

 * Damage: 5 HP
 * Health: 4 HP
 * Found In: Grasstown

Don't be worried about these guys. While they may cause moderate damage, you can only be hurt if you run into them. They float around in predetermined patterns and never really stray far away from where they start. Pick them off from afar. They are only found after talking to Chaco in Grasstown.

Giant Jelly

 * Damage: 6 HP
 * Health: 50 HP
 * Found In: Grasstown

The giant jelly likes to use similar tactics as the dive bomb bats but it moves much slower and floats side to side when it is coming down. It is best to pick it off from below while moving side to side so it doesn't know where to come down on you. The giant jelly drops Jellyfish Juice as many times as you want. It is only found after talking to Chaco in Grasstown.

Mannan

 * Damage: 3 HP
 * Health: 11 HP
 * Found In: Grasstown

Fighting these guys is pretty easy. Although they look intimidating by the numbers that they come in, they don't move at all. Also, they will not attack you unless you attack them, and even then they only shoot out an easy to avoid ring of energy in the direction they are facing. Just jump over them and keep on shooting in the back.

Frog

 * Damage: 3 HP
 * Health: 10 HP
 * Found In: Grasstown

The frog isn't very threatening when solitary. They simply bounce towards you and turn around if you jump past them. However, they are a pain in the neck in situations involving many enemies. Take out these guys as soon as possible to save yourself a headache.

Puchi

 * Damage: 1 HP
 * Health: 2 HP
 * Found In: Grasstown (Balfrog fight)

The puchi is a miniature frog that bounces around. It has much less health and inflicts little damage. They can be a nuisance when dodging attacks if they are not killed quickly.

Polish

 * Damage: 10
 * Health: 24
 * Found In: Sand Zone

Try not to get hit by these guys, they deal a lot of damage. when they die, they split into many baby Polishes so watch out for that.

Baby Polish

 * Damage: 3
 * Health: 2
 * Found In: Sand Zone

When you defeat a Polish, 10 of these are released.

Sandcroc

 * Damage: 10
 * Health: 30
 * Found In: Sand Zone

These crocodile-esque sand beasts are a pain, quite literally, if they get you. They appear when walking on areas of sand which are marked by a skull and bones. You can avoid them by running at full speed, and their snaps will miss. Jumping can only save you if you jump at the exact moment you hit the ground. They stay up until you shoot them, and you can safely use them as a platform. It is not recommended to shoot at them after they snap at you, because it will sink back into the sand and will attack you again.

Crow

 * Damage: 4
 * Health: 20
 * Found In: Sand Zone

These guys are a bit annoying at times. They sometimes hold skullheads, in which case the safest way to kill them is to stand below them and shoot them. When you shoot them, they follow you, and try to make you touch them.

Armadillo

 * Damage: 6 HP
 * Health: 20
 * Found In: Sand Zone

The armadillo will hide inside its shell when you fire a missile, making it impervious to damage.

Skeleton

 * Damage:
 * Bone: 4 HP
 * Touch: 6 HP
 * Health: 40
 * Found In: Sand Zone

The skeleton will jump around the local area, and will shoot some bones at Quote every three jumps.

Skullhead

 * Damage:
 * Health:
 * Found In: Sand Zone

The skull head will jump back and forth trying to bite whatever enters its jaws.

Skullstep

 * Damage: 8 HP
 * Health: 20
 * Each Leg: 6
 * Body: 12[?]
 * Found In: Sand Zone

The skullstep will walk back and forth. When both legs are destroyed, it will revert to a skullhead for a short time before selfdestructing.

Gaudi

 * Damage: 5
 * Health: 15
 * Found In: Labyrinth

The gaudi are roach-like humanoids found within the Labyrinth. As scavengers, they have crafted a city from the various junk located within the labyrinth. Some Gaudi are known to hover in mid-air and launch attacks from a distance.

Armor Gaudi

 * Damage:
 * Shurkin: 3 HP
 * Touch: 5 HP
 * Health: 15[?]
 * Found In: Labyrinth

Some Gaudi wear armor in addition to their exoskeleton. In addition, they will throw Shurkins at their target. You can only attack them when they jump into the air so the polar star upgrades should kill it before it tries to hit you with the Shurkins.

Gaudi Egg

 * Damage: No damage
 * Health: 11
 * Found In: Labyrinth

The Gaudi Egg is the initial gestation of Gaudi. They are defenseless and are protected by nearby Gaudis. They can give you good power ups if you defeat them such as 3 hearts, 3 missiles and 5 exp.

Fire Whirrr

 * Damage:
 * Fire Ring: 5 HP
 * Touch: 10 HP
 * Health: 50
 * Found In: Labyrinth

The Fire Whirrr is a defensive platform that shoots rings of flames.

Buyobuyo Base

 * Damage:
 * Smaller Buyobuyo: 3 HP
 * Touch: 1 HP
 * HP:

The Buyobuyo base is an unknown organism that is attached to the floor or ceiling. It shoots smaller Buyobuyo which then try to attack a nearby hostile.

Fuzz

 * Damage: 1
 * Health: 8
 * Found In: Labyrinth

A Gaudi spirit. They won't stop moving when you shoot them.

Fuzz Core

 * Damage: 1
 * Health: 10
 * Found In: Labyrinth

A clump of Gaudi spirits. When it is destroyed, the five Fuzzes will break formation and attack.

Porcupine Fish

 * Damage: 3
 * Health: 4
 * Found In: Reservoir

A small fish found in the Reservoir. It defends itelf by expanding it's quills.

Hopper

 * Damage: 4
 * Health: 12
 * Found In: Outer wall

A hopper will jump along the outer wall, falling to the left rather than downward.

Night Spirit

 * Damage: ?
 * Health: 64

A spirit floating around the outer wall. Occasionally, the spirit will launch an attack consisting of numerous indestructible projectiles spread across a small area.

Midorin

 * Damage: 3
 * Health: 16
 * Found in: Plantation

A photosynthetic warrior walking back and forth within the plantation. If you land on their head correctly, you will not be hurt, and you can ride on them.

Droll

 * Damage: 1
 * Health: 18

A passive guard that only attacks in retaliation.

Spitting Gunfish

 * Water stream: 3
 * Health: 32
 * Found In: Plantation

A fish in the lower water reserve of the plantation, that serves as a platform for some users. It charges up and fires a stream of water, made up of projectiles similar to that of the level 2 Bubbler.

Orangebell

 * Damage: 2
 * Health: 64
 * Found in: Plantation

A large bat within the plantation, with an escort of smaller bats.

Rabil

 * Damage:
 * Jump: None
 * Lunge: 5 HP
 * Health: 40

Rabil is a Mimiga that is under the influence of the demon petal, and attacks by charging and jumping.

Igor

 * Health: 300
 * Damage: ?
 * Energy Balls: 2 HP
 * Contact with him: 5 HP

Igor returns on the balcony as a regular opponent. He is super annoying, all because of his high 300 HP, and he shoots about 15 white orbs at you when you run away from him.

Bute
A bute is a small humanoid. There are three types of them. One of them is armed with a spear, attempting to crash into player. Second type moves along the ground and tries to leap attack the player with a sword. Third type is stationary and is armed with a bow and arrow. The spear one does 5 damage and can be easily killed. The arrow one deals 8 damage per shot, and 3 contact damage. It doesn't move around and has an delay of 3 seconds between shots. The one with a sword can only be attacked while it's charging so don't waste your time shooting it when it's standing still.

Mesa


A mesa is a large humanoid, who pickups a ground tile to throw at the player. It has around 60 health and it's blocks do 10 damage but they only throw at a certain place so just get up close (but not to close) and keep on attacking until it dies.

Green Devil


A green devil is an enemy that simply flies across the room.

Rolling

 * Damage: 6 HP
 * Health: Indestructable

This enemy follows a simple pattern. It moves forward, and turns right when it hits a wall.

Deleet

 * Damage: 12 HP (explosion)

The deleet is located on a wall within the Sacred grounds. When hit enough times, it will become indestructible and countdown from 5 before exploding (destroying the wall with it.)

Balrog (Shack)
Damage
 * HP:60
 * Jumping attack: 2 HP
 * Running attack: 2 HP

He charges 2 times then jumps. Just shoot him and jump over him when he charges at you. Be wary of when he jumps in the air because he could connect with you as you are jumping. The reward for fighting Balrog is 5 experience points for your weapon.

Igor
Damage Use the same tactics that you used for the first fight against Balrog. The only real difference is that he may occasionally open his mouth, in which you should either jump over him immediately or run away. If you don't have a level 3 Polar Star, this battle will be hard. **NOTE** Igor is found on the balcony as a regular enemy after eating ANOTHER red flower.
 * HP:300
 * Energy Balls: 2 HP
 * Contact with him: 2 HP

Balrog (Power Room)
Damage
 * HP: 240
 * Energy Orbs: 2 HP
 * Contact with him: 2 HP
 * Landing upon: 10 HP

This fight is pretty easy. Balrog will just jump and fly over you for roughly three seconds before falling down. Just shoot him when he passes over you and when he lands on the ground. Be wary when he spits out the energy orbs but one shot from any weapon will destroy them. If you have the level 3 Bubbler at this point, this fight will be a simple affair, due to the fact that this weapon can hit him hard if you let it charge, and blocks his energy orbs. Another good strategy is to use the level 3 Fireball because when Balrog starts to fly you can jump on him for no damage and use the Fireball which also allows him to have no defense. As he falls jump off and use the Fireball again when he shoots out energy orbs so they shouldn't hit you. Careful when his health is 1/4! He doesn't fly! He just jumps, but still shoots orbs. Best way to do that, is getting the Fireball out, and then shoot him, and he's defeated!

Balfrog

 * Damage
 * Energy Orbs: 4 HP
 * Contact with him: 5 HP

From the fans, spam level 3 Fireballs into his mouth.
 * Fireball strategy

The easiest way to kill Balrog (or Balfrog) at this point is to use a level three bubble gun and just sit in the fans, firing madly as he approaches. You won't damage him like this, but it will kill the smaller frogs on the ground. Once he is close, use the fan you're in to jump over him, still firing to clear the way on the ground. He should open his mouth--get as close as you can and just pump fireballs into him. Too close and they won't hit his mouth, though, so watch out! Also, if you have the level three Bubbler, it is possible to use that for the battle, because the bubbles it generates deal 3 damage when shot (which is almost as much as the level three Fireball, plus you can generate many of them at once). As for the smaller frogs, they have very little health, and a few bubbles can get rid of them.
 * Bubbler/Fireball strategy

You can use Missiles, but if they hit his energy orbs they won't hit him--so many players choose just to use the Fireball, or the Bubbler. Once his health is half depleted, he'll make larger jumps, bringing down larger frogs--just be more careful than you were before, and you'll win easily.

Curly Brace

 * Damage:
 * HP: 320
 * Contact with Mimiga: 2 HP
 * Machine Gun shot: 6 HP
 * No contact damage

Curly has a simple strategy: she runs around and shoots you every now and then. This battle is more irritating than hard. Using the Polar Star or Fireball, shoot out the mimigas to get to Curly and avoid their attacks. Then with the Fireball, attack Curly with full force (do not try to use missiles, she has a shield). She'll occasionally begin to flash, signaling the beginning of her only attack: her machine gun will fire a burst that you can just barely jump over. Keep in mind that jumping over her is a bad idea, because she can shoot upwards.

Omega

 * Health: 300
 * Damage:
 * Spheres: 4 HP
 * Stomp: 20 HP
 * Bite: 20 HP

Omega is one of the first hard bosses, assuming you had no problems with Balfrog. to kill him for the first time and second time he come out use the polar star then just spam and reload the bubbler are the most useful in the beginning of the fight; you can deal 150 damage to him very easily if they are level three, simply by standing right next to him and pumping him full of shots while he releases dirt spheres (whatever they are) into the air. After he goes under, shoot out the dirt spheres--the machine gun is good for this if you have it, as is the level 3 bubbler--and then be prepared for him to pop up somewhere. You can only hurt him when his maw is open, so wait for that before you begin firing.

After he has lost about half of his health, he'll come out of the sand and begin to jump around, all the while launching dirt spheres. Watch out for him when he jumps so he won't land on you! While this makes it harder for you to survive, it also make it easier to damage him since he can be damaged while his mouth is closed. Use your machine gun, missiles, or fireballs (if you are good with them) to finish him off. The dirt spheres will give you experience, health and missiles if you destroy them, so take advantage of it! Before you know it, Omega will be dead and gone.

Alternately, you could pump him full of level three machine gun right off the bat, and get him down to half-health before he tries to attack you for the first time. Just alternate from shooting at the dirt spheres to shooting Omega when his maw is open and he should be dead in no time.

Another good way of defeating Omega is to use the level 3 Fireballs. When he pops out, start blasting fireballs like crazy. Do this until he is defeated.

Frenzied Toroko

 * Attacks/Damage
 * Touch: 5 HP
 * Blocks: 10 HP
 * Contact with flower: 1 HP

Frenzied Toroko can be a hard battle. It's best to max out your weapon levels before you head in. She basically runs and jumps around, throwing blocks straight at you constantly. You should keep moving, and always keep an eye for the flying blocks, since beside the significant damage, your weapon is going to level down if you're hit. When she jumps, a good strategy is to run past her from below, since you won't get hit by a block that way. The flowers only have 1 HP, so they're not that dangerous, and they provide minor EXP and health.

Note: when you hit her with a missile she will speed up slightly (as is the case with most boss fights).

Puu Black
Damage
 * Landing upon: 20 HP
 * Bubbles: 5 HP

He can jump on you, which does 20 damage. When the black bubbles starting to fall, dodge to the side as he is going to land. Use the Missiles against him to finish this battle with ease. Machine Gun, Snake, or Polar Star will do as well. Another good strategy is to use the level 3 Blade to destroy his bubbles, and damage him in the process. Keep shooting him until he jumps through the screen, then move like crazy. When he's down, be careful not to touch the still-boiling black bubbles; it still does damage until he's completely gone.

Fun fact: He has the shape of Balrog, therefore, he could be related to him somehow.

Another fun fact: If you won against the battle of Ballos, in the credits, instead of Balrog being the doctor, Puu Black is!

Monster X
Damage
 * Run Over: 10 HP
 * Missiles: 5 HP

Monster X is the toughest boss you'll meet before you take on the Core. Damage is really high, as well as the speed. Destroying him will take a while since you have two painful steps. First off, destroy the green spots on him when he first opens up. Blade works best for these, but it will come in handy later in the fight so it's advisable to pick another high damage gun. Monster X will shoot at you, so be careful. If you want to be very cautious or replenish resources, the bubbler shield tactic will also work.

After that's done, the next time he opens up, use your missile launcher and shoot the face. Unfortunately, green missiles will be shot everywhere. Level 3 Blade will easily wipe out all missiles on screen, leaving you safe to go back and shoot at the face.His health begins to get low very quickly when using weapons such as the Blade.

Balrog (Boulder Chamber)
Damage
 * Rockets: 5 HP
 * Contact with him: 5 HP

Curly will be wiped out, so you're on your own. Unlike the past fights, Balrog will now start shooting missiles at you. What you can try doing is to use your missiles and shoot him. If you run out, you might as well choose another gun. Fireballs are okay when he's on the ground. Balrog attacks in a pattern: charges at you, then jumps and shoots missiles. The only way he can snatch you is if you are under him or if you jump into him. Level 3 blade is good for taking out the missiles.

The Core
Damage
 * Energy Balls: 20 HP
 * Small energy balls: 3 HP

The Core can be quite difficult. Oddly, for some people, this fight is very easy compared to the other boss fights. The core and its mini-cores deal no touch damage, and for the most part only shoot small energy balls. By the time you fight this boss, you should have 41 HP, which is far more than enough. The large energy balls however, can tear your HP down incredibly fast (But you shouldn't worry; he doesn't use them often). There's also the threat of drowning, which is made prominent by how the Core tends to flood the entire map with water for long periods of time. If you have the Machine Gun or picked up the Booster v0.8, this should be absolutely no problem at all. But if you want the best of the best, this boss fight can be hard.

A good strategy here is weapon choice. If you stick with only one gun for the whole fight, you won't deal much damage, and the boss fight will be hard. If you picked up the Machine Gun, just pelt the Core's face when it's open. If it gets closer, the level 2 blade, combined with rapid button pressing, can tear down it's HP much faster than you think it would. If the Core floats down to the lower levels, some level 3 Fireballs (If you didn't get the Snake) can do some massive damage as well. If you picked up the Bubbler, it can make an awesome shield while you're picking up items. Strategic Missile usage is a good idea, but if you really feel like it, you can just spam the Missiles to take out a chunk of its HP at the very start, making the rest of the fight easier for you. Depending on how much missiles you have, you can tear up 1/4th to 3/8ths of its health with an initial Missile spam. If you're going for the Spur and therefore still have the Polar Star, don't use it. It simply is not powerful enough. Stick to the other weapons.

By the first time he pins you to the back wall, his health should be below 1/4th, he's going down fast, isn't he? Some more Blades/Fireballs and he should be dead.

Ironhead
Damage
 * Contact With: 5-10 HP
 * Blocks: 10 HP

Ironhead is really a miniboss. You can use missiles here, but I wouldn't risk it unless you're at very close range, since there's blocks all over. Stick with another gun for now. Ironhead can't be really hard, so try fighting him like you did with some past minibosses. A lvl 3 Blade can dish out a LOT of damage and end this fight rather quickly since the high amounts of mini-fishes will spread and make the sword effect do a lot of damage.

Fun fact: Ironhead is a full boss in one of studio pixel's other games.

If you can defeat him without taking damage, you get an Alien Medal.

Ma Pignon
Damage
 * Contact With: 5 HP
 * Boulders: 10 HP

He's really a shrimp, but you must fight him to get into the Sacred Grounds. If you don't, Curly won't join you underground. At first, he'll jump around and bash his head into the wall to cause falling boulders. His head will be stuck, so shoot him there. Once in a while, he'll summon clones of him, so destroy the clones to find the real Ma Pignon. Your reward is himself to feed to Curly.

Red Demon
Damage
 * Contact with: 10
 * Flying Axes: 6

This guy isn't so hard. He's only like the Drolls. However, he throws more than one, so be careful! He should be easy to take down. Use the Spur/Nemesis in this fight. Nemesis can work better, because there are no enemies in this fight. Machine Gun also works. When you beat him, you'll find a chest. Open it; it contains the Clay Figure Medal.

Misery
Health: 500

Damage:
 * Rings: 2 HP
 * Blocks: 10 HP
 * Thunderbolt: 10 HP
 * Contact with thunder ball: 6 HP
 * Bubble Ray: 6 HP
 * Contact With Her: 1 HP

Finally, a fight with Misery! As a nearly end boss, she's not easy to deal with. Her attacks are quite strong, as well as her magic. Take out your Nemesis, Spur, Machine Gun, Snake — whatever you have. However, I would recommend the Nemesis, or charged Spur. As she floats in the air, shoot her from underneath. That way you can deal more damage. She'll always shoot a bubble ray at you unless it’s every third strike, which makes the attack a falling brick. When she reappears after teleporting, if she is a certain distance away from you, she will summon three floating black orbs that shoot lightning down at you if you pass under them. Simply walk or air-dash under all three orbs without hesitating, and their lightning blasts will miss you.

Once 1/3 of her HP is off, when she reappears after teleporting, she will summon two rings that orbit around her and deflect incoming shots, so time your attacks carefully. If 2/3 is taken, she will summon four rings instead of two. After she attacks, these rings turn into bats which you can shoot for powerups, so take advantage of that.

The Doctor
Damage
 * Red Crystal: 1 HP
 * Red Energy: 5 HP
 * Contact with: 10 HP

The Doctor can be hard if the battle takes a while. With the Red Crystal in his hands, he can be quite strong. One of your choices would be to use the Missile Launcher. If at level 3, the Doctor will be wiped out easily. But doing that would be bad. You'll need that Missile Launcher for either the Frenzied Doctor or the Undead Core. The other choice would be to use another gun. When fighting the Doctor, take him down quick and look out for his attacks. He will eventually shoot red energy at you. After a while he'll be in the center of the air and spread red energy all over. Any time there is no red energy, he is vulnerable.

After the Doctor is down, he'll upgrade to Muscle Doctor. In this mode, he cannot really shoot energy at you. His attacks are usually in this order: jump at you, teleport, charge at you, jump at you, and so on. After a while he will shoot out red bats that can be easily destroyed if you shoot them with the Nemesis or Polar Star upgrade (they don't give you any power ups) I suggest using the missiles here, since the next boss you can use spur or nemesis. A flurry of level 3 missiles can take him down in no time; if you're short on missiles, then a level 3 or MAX Spur is a good alternative too.

Sue, Misery, and the Undead Core

 * Damage
 * Sue
 * Somersault: 4 HP
 * Misery
 * Bats: 2 HP
 * Critters: 2 HP
 * Fish Missiles: 3 HP
 * Undead Core
 * Health: 695
 * Fireballs: 5 HP
 * Blasts along the floor and the ceiling: 4 HP
 * Energy Balls: 10 HP

This is the final boss for those who are not doing the secret area. It's practically a three way boss, with the Undead Core as your main target. Sue and Misery are there to help him fight you. Sue annoys you by twirling towards you. Misery, if either her or Sue are hurt, will summon bats and critters; and if Sue is down first, Misery will start to summon homing missiles, which are much harder to deal with then the critters. Therefore a good strategy is to focus the shots on Misery first.

Like the normal core, when the Doctor shows his face, shoot him. He does not appear for long, so use the time wisely. The blasts along the floor are easy: just avoid being on the floor. The fireballs are tougher, since they absorb shots; if he shoots fireballs, focus on dodging rather than dealing damage. When he gets low on HP, he opens his mouth, and he will perform the Energy Ball attack similar to the Core's, but will keep the mouth open continually for the rest of the fight, making it more risky to use the Spur, as it has no splash damage.

Heavy Press
Damage
 * Lightning Bolt: 10 HP
 * Contact With: 10 HP, or Instant Kill if falling

Heavy Press may look like a hard boss, but he's really not unless you don't have the missile launcher or spur. At Sacred Grounds I, you should have the missile launcher at level 2. At that point, your missiles should be strong enough to kill Heavy Press. Charging the spur, shooting him, then dodging and shooting again works pretty well too. He has companions, such as the Roller and the Butes. Once Heavy Press is dead, he'll fall as a normal press — a pound would be 127 damage, so stay out of the way!

Ballos

 * Damage
 * Contact with: 10 HP
 * Lightning Bolt(1st form): 10 HP
 * Skull Blasts(1st form): 4 HP
 * Landing upon(2nd form): 16 HP
 * Spiked Spheres: 14 HP (3rd form), 10 HP (4th form)

This is it — the final boss! Like any final boss in any game, Ballos is very tough. He will have four forms for you to deal with.

Let's start with form one: himself. Eventually he will charge at you. He follows a basic strategy: charge at you, jump in the air, charge at you, and pound you down to the ground, and it repeats over and over. While he is doing this, shoot him with Nemesis or Spur. If he is not dead for about 8 times he performs his strategy, he'll hang in the air and shoot lightning at you. He'll leave a target to aim at you, so move fast. At form two, he'll crash through the ceiling and come back down as his HUGE head. The only thing he can do is jump around making bones pop through the ground. This is probably his easiest form. I suggest using your spur or nemesis here. Jump onto his eyes and shoot at it. Don't hold onto him while he jumps, or you'll get hurt by green innocent devils flying around. After that, he'll grow spiked spheres around him. There's really nothing to drop. Just shoot the balls until they close their eyes. Ballos will roll all over the map, and when he rolls on the ceiling, he'll drop skull bombs on you. Don't touch the spiked balls either, or you'll get -14. Once all spheres are closed, he will float in the middle. The ground is covered in spikes, there are platforms all over him — it's the final form! The spiked spheres will stick onto him and will be hurled at you. His eyes are gleaming bloody red, and red butes will go after you. Hang onto his eyes and shoot into it with missiles, or whatever you've got. After that…you're done!

Press
The press remains inert until the player shoots the block supporting it or walks directly underneath it. At that point, it will immediately slam towards the floor. Standing below the press while it falls to the floor causes instant death.

Toroko
When you enter the shack, Toroko mistakes you for the doctor and attempts to attack you, she can do minor damage on contact, after she runs far enough she begins to run in circles, shoot her one time with the polar star at any level and she'll fall over.

Note: in Cave Story+ you actually earn a steam achievement if Toroko manages to kill you.