Contra/Enemies

Infantry

Soldier	Gunner
Soldiers run across the screen and jump when they reach a ledge. They may fire bullets at you occasionally. In bases, they run or jump across the background, stopping to shoot at you before they leave.	Gunners stand in place and fire at you with much better aim than the other enemies. They can fire in any direction.
Scuba Soldier	Jet-pack soldier
They attack by firing a shell into the air that splits into three pieces before it hits the ground. It is difficult if not impossible to kill these guys. However, they can only fire directly upwards, so their bombs are usually easy to avoid.	Jet-Pack soldiers don't appear until after the second base. They fly overhead and try to shoot down at you when they get the chance.

Artillery

Wall turret	Cannon
Gray boxes with a rotating cannon are very common in the first half of the game. They're quite easy to destroy since they have a limited number of firing directions. They're initially inactive but when you get close to them, they'll activate and start firing at you.	Cannons pop out of the ground when you are within firing range. They can only fire ahead, and you are safe shooting at them when you crouch because their bullets fly over you.
Defense cannon	Base turret
Defense cannons only appear right outside of the entrance to the first base. Two of these will lob explosives at the ground in an arc. In order to have clear access to the door below, you should destroy these cannons first.	Stationary guns with a red light on top appear in almost every room in the bases. They fire only occasionally but combined with all the other things that'll appear in any given room, they can be a challenge to avoid.

Base features

Lock seal	Mines
The locks which open doors to subsequent rooms in each base are covered by a seal. The seal also protects the power to the room, which prevents you from advancing. In order to kill the power and open each door, you must destroy the seal by shooting it.	Mines will slowly roll toward you from the back of the rooms, sometimes in a line, but usually randomly. You can jump over them with good timing, but it's usually easier to duck and destroy them with a few shots. They can also be tossed by soldiers as they run across the back of the screen.
Defense bot 1	Defense bot 2
White defense bots appear when you invade the power core of the second base. They run out from the sides, and leap down to stop you. Destroy them before they reach the floor.	Red defense bots also appear when the white bots do. However, instead of leaping down to the floor, they stay above and shoot at you in an effort to disrupt your assault on the core.

Heavy artillery

Gunner	Heavily armored vehicle
Gunners attack from stationary cannons that fire large bullets at you. The bullets are fast, but the gunner pauses after firing three shots, giving you time to move into position. You can avoid getting shot by crouching.	These vehicles roll onto the screen, stop about halfway, fire bullets for a few seconds, and then slowly continue to the left. They have limited firing range, and you cannot jump over them. You must shoot at them continuously in order to destroy them before they run you over.

Spoiler warning! This section of the article contains spoilers, or hints about the game's storyline or progression.

You might want to skip down to the next heading if you do not want facts about the game's storyline or plot revealed to you.

Spoilers!

Spoiler warning! This section of the article contains spoilers, or hints about the game's storyline or progression.

You might want to skip down to the next heading if you do not want facts about the game's storyline or plot revealed to you.

Aliens

Alien head	Floaters
This large mouth reaches down from the ceiling of the entrance to the alien lair. It prevents anyone from getting past by flooding the area with Floaters. It must be destroyed before you can get deeper into the heart of the breeding grounds.	Floating aliens slowly move around and try to run into you; they have no other form of attack. They're easily destroyed, but be sure to take them out quickly, as larger numbers can overwhelm you.
Alien mouths	Spores
The alien version of a turret, it is attached to floors and ceilings and attack by creating spores that home in on you rather quickly if you don't destroy them. They are stationary, but take a few shots to destroy.	Spores are smaller than floaters, and they are much faster. They travel straight for you, and typically end up moving into your line of fire. Watch out for the few that slip by.
Egg hatch	Crawlers
Egg hatches release baby aliens in the form of Crawlers. They must be destroyed in order to prevent further Crawlers from appearing and interfering with you mission.	Crawlers hop out of the hatches and run along the floor to reach you, or run across the ceiling and dive down at you. They will defend the heart that feeds the alien base with their lives.

Bosses

Ocular fire	Shadow Beast entrance
The boss of the first base, you will have to destroy this single eye, which can launch a ring of fire down to the bottom of the screen, before you can advance to the waterfall beyond. But first, you will have to take out the four power cores and two sets of guns that protect it.	When you reach the top of the waterfall, you will have to crack your way into the second base. Guarding the entrance is a large statue with a target at the top protected by one array of guns in the center, and two turrets on either side.
Anti-gravity transport	Armored giant
The anti-gravity transport flies in over the snowfield beyond Base 2, and opens up to reveal a never-ending supply of soldiers who fly out to attack you. Bombs drop from the center. You must take the shuttle out to advance.	You will face not one, but two of these hulking brutes as you attempt to pass through the industrial heart of the enemy's headquarters. They throw disk-like mines, and the second giant has more throwing techniques than the first.
Alien heart
After fighting through jungle, bases, waterfalls, and snowfields, you will reach the literal heart of the alien territory. You will find a gigantic pumping heart that provides blood to the cocoons of aliens that have yet to be born. In order to succeed in your mission, the heart must be destroyed before the Red Falcon menace takes over the world.