Gradius 2/Gameplay

Controls

 * Joystick or Direction Pad: Use the joystick or direction pad to pilot the Metalion in any one of eight directions. Although the screen scrolls forward automatically, you can travel to any visible portion of the screen.  However, you cannot collide with any part of the terrain, so you must steer clear of any obstacles that occupy your path.
 * Fire: Press the fire button to shoot your primary weapon, such as shots or lasers. You also press the fire button to launch missiles to the ground if the Missile power-up is enabled.  Holding the button down allows you to fire continuously, although it's possible to fire more rapidly than holding the button down ordinarily allows.  Holding the button down with laser beams allows you to fire the longest possible uninterrupted beam.
 * Power-Up: Press the power-up button when you would like to activate whichever selection is highlighted in the power-up bar at the bottom of the screen. You can only use the Power-Up button when a selection is highlighted, and the words are present in the power-up indicator shown to the right.

The Metalion
You are the pilot of the Metalion, a ship which was modeled after the Vic Viper due to its success in the original Gradius event. While the physical structure of the ship and its flight capabilities remain more or less the same, the Metalion has a far more flexible power system, which is capable of absorbing abilities into its system that it did not originally launch with. You must fly the Metalion through invading alien territory in an effort to defeat Venom and put an end to his galaxy conquering ways. Like the Vic Viper, the Metalion does not launch with anywhere near full capacity fire power. The Metalion can tap into energy deposits left behind by destroyed enemies (the power-up capsules) to drive weapon enhancement technology. When the Metalion is launched, it's starts the mission out at the slowest speed with only the most basic weaponry. You must collect the power-up capsules and strategically tap into the weapon enhancements in order to build upon the destructive power of the Metalion and steadily increase your offensive abilities. Below are the explanations of all of the power-ups available to your craft.

Power-Ups
Throughout the game, the Power-Up bar can be seen at the bottom of the screen. It identifies the selections that you may choose to power the Metalion with. In order to choose a power-up, you must collect the power-up capsules that enemies leave behind. For each item that you pick up, a selection will be highlighted, starting with "Speed Up", and continuing to the right one space at a time. If you collect another power-up capsule when "Force Field" is highlighted, the selection will wrap around to the left and highlight "Speed Up" again. Whenever a selection that you would like to choose is highlighted, you press the Power-Up button to activate it. All of the power-ups are described in detail below.

Power-up capsules are left behind by different types of enemies. One type of enemy that leaves power-up capsules are formation enemies; enemies that come out in large groups or chains. If every enemy in the formation must be defeated, the last enemy defeated will leave a power-up capsule behind. The other type of enemy that provides power-up capsules are alternatively red colored enemies. Most enemies have a standard color, usually some variant of gray. However, when an enemy is predominantly colored red, that is an indication that the enemy will leave a capsule behind when destroyed.

While most such enemies produce a red power-up capsule, select designated enemies will deposit a blue crash capsule instead. Running into the crash capsule will destroy every basic enemy present on the screen at that time. It will not affect your power-up bar in anyway. Since the moments when they occur are predetermined, you can work them into your strategy to complete a stage. They can save you during very difficult moments.

Speed Up
Speed Up naturally increases the speed at which you may maneuver your ship across the screen. The more Speed Ups you apply to the Metalion, the faster it can fly around obstacles and enemies, or line up with oncoming enemy crafts. The Speed Up power-up can be selected seven times before it depletes. However, you should not apply this power-up to its maximum ability. Doing so will cause a condition known as "over control," which occurs when the ship moves too quickly for you to make meaningful adjustments to its position in space. Every player has a speed at which they are most comfortable guiding the ship through obstacles. Do not select a faster speed than you are comfortable handling.

Missile
If you activate the missile power-up, the Metalion (and every Option that you have) will drop a missile down towards the bottom of the screen. The missile or missiles continue to drop down until they fall off the bottom of the screen, or until they land on the surface of some terrain. They will continue to coast along the terrain as long as the terrain is flat or slopes downhill. They will explode if they come into contact with an enemy, doing enough damage to destroy most basic enemies. This power-up can be upgraded by selecting it a second time, at which point the missiles will speed up considerably. Only one set of missiles can exist on the screen at one time. The next set of missiles will not be fired off until all of the previous missiles have dispersed.

Double
Ordinarily, the Metalion can fire off two shots on the screen at one time. If you activate the double shot power-up, one of the shots will be directed up to the ceiling at a 45° angle and fire simultaneously with a regular shot. This effectively increases the range of your gun while at the same time decreasing the efficiency of your fire straight ahead. Both bullets must disappear before the Metalion (or any Option) is capable of firing a double-shot again. Selecting Double replaces the Laser power-up, and causes Laser to reappear in the Power-Up bar; you cannot have both power-ups active at one time.

Laser
If you activate the laser beam power-up, the regular shots of the Metalion will be replaced with a long powerful laser beam. When first selected, these beams will extend to approximately half the length of the screen. This power can be updated by selecting it a second time, at which point the beams will extend to nearly the full length of the screen. The beam will travel up and down with the height of its originator, even after the beam terminates and flies forward on its own. The beam will strike any enemy that it hits, usually destroying any basic enemy that it comes in contact with. Due to the limitations of the game's hardware, the laser does not always detect collisions along every segment of the beam, which can cause it to miss critical weak points of larger enemies. Selecting Laser replaces the Double power-up, and causes Double to reappear in the Power-Up bar; you cannot have both power-ups active at one time.

Option
When you activate an option power-up, a small orange ball begins to follow behind your ship. This ball, known as an option, contains every bit of fire power that the Metalion ever has. If the Metalion powers up, so do any of the Options. Options are primarily used to increase your offensive power, but they can also be used to safely destroy objects in positions that the Metalion cannot proceed to. The Options typically follow your ship in a snake like way, trailing behind in the ship's previous positions. Small adjustments to the ship's position causes the options to similarly adjust themselves. You can activate up to a maximum of two Options. However, the enemies attack you with a firepower that is proportional to your perceived threat. Therefore, the more Options you have activated, the more aggressively the enemies will attack you.

Force Field
The final power-up on the bar activates a shield. When activated, the two small shields appear in front of the Metalion. They can absorb a large number of enemy bullets and collision. When the shield can absorb only one more hit before disappearing, it turns red. Eventually, they will disappear, indicating that the benefits of the shield have ended. At that time, the last position of the Power-Up bar will fill back up, allowing you to select it again. Note that the shield only effectively blocks attack from the front of the ship. The Metalion is still vulnerable to attacks focused on the rear of the ship.

Upgrade powers
At the end of each stage, you must defeat a large mother ship before you can advance to the next stage. If you destroy the core of this ship in under 30 seconds, you can invade the core in an attempt to obtain an additional power for the Metalion. If you manage to destroy the core in under 15 seconds, you can obtain two additional powers. To absorb any powers, you must first survive a trip through the interior of the mothership and reach the power supply of the core.

The argument against collecting upgrade power-up: Note that many of the power-ups you obtain from a mothership end up extending the length of your power meter. New power-ups are inserted somewhere between Missiles and Lasers. As a result, when you are fully powered up, you are required to collect eight power-up capsules to activate an Option, as opposed to the five power-ups it normally takes. This significantly increases the effort it takes to power back up if you happen to die and lose all of your firepower. As a result, it may be better to identify the one or two power-ups that you can't live without, and stop collecting anymore in order to keep the meter length as small as possible. The order in which the power-ups are presented below are the order in which you will obtain them.

Up Laser
The Up Laser is a horizontal beam which originates from the top of the Metalion and travels straight up towards the top of the screen. The beam is roughly the size of the Metalion. This power can be updated by selecting it a second time. When you upgrade the beam, it expands in size as it rises allowing it to hit more targets. Selecting the Up Laser will disable any Double weapon you may have currently selected.

Down Laser
The Down Laser beam is exactly like the Up Laser beam, except that it travels down to the bottom of the screen. Like the Up Laser, it can be upgraded the same way by selecting it twice. Selecting Down Laser will disable any Missile weapon you may have currently selected.

Napalm Missiles
If you invade the cores of boss ships, you can eventually absorb the power to fire napalm missiles. These missiles behave just like normal missiles, with one exception. If they strike an enemy, they explode in a fireball that lingers and can destroy other enemies that wander into the explosion.

Reflex Ring
The Reflex Ring is an upgrade to the Double weapon. Upon selecting it, your upward shot and forward shots are combined into a single blast that travels forward and then boomerangs back to the Metalion (or an Option). The rings travel approximately a third of the way across the screen before returning, making the weapon a poor choice for long distance targets.

Extend Laser
The Extend Laser is a second upgrade to the Laser weapon. Upon selecting it, the single beam laser is replaced by a double beam which travels the same length of the screen as the upgraded laser weapon. The additional beam gives this weapon added width, making it easier to strike enemies.

Back Beam
The Back Beam is a weapon similar in function to the Double weapon, except that it fires directly behind the Metalion. The Back Beam replaces any Double or Laser weapon you may have currently selected.

Fire Blaster
The Fire Blaster is the last upgrade weapon that you can obtain, and the final upgrade to the Double weapon. Selecting it replaces the Reflex Ring with a stream of fire that extends forward from the Metalion. In a similar fashion to a blade, it destroys any enemy caught up in the flame. After being fired, the flame extends a short distance ahead of the Metalion, before retracting back to the ship. You can keep the flame fully extended by continuously tapping the fire button. (Note that a bug in the original game keeps this weapon from working as it should, and it will definitely not destroy particle terrain, which can cause you to crash.)

Time limited upgrades
The following upgrades can be found at particular locations throughout certain stages. Upon collecting them, they grant the Metalion with a power-up that is limited in duration to 15 seconds. After the 15 seconds pass, the power they grant ends, and the Metalion returns to its former state.

Vector Laser
The Vector Laser is a vertical beam that is fired forward from the Metalion. It starts out fairly small, but as it travels forward, it extends in height (reminiscent of the Ripple weapon introduced in Salamander and Gradius II). It wipes out anything that crosses its path.

Option Barrier
By collecting this power up, any options that may be activated will begin to circle around the Metalion. They will maintain this circular path around the ship regardless of where the ship travels throughout the screen.

Enemy Slow
Upon grabbing this power up, all enemy activity on the screen will be slowed down to half speed for the next fifteen seconds. This includes any projectiles that have been fired by the enemies. Your ship and any weapon you fire will continue to travel at full speed.

Rotary Drill
Collecting the Rotary Drill causes the Metalion is spin around like a drill. Any terrain particle that can ordinarily be shot with weapons can instead be destroyed by physical contact with the Metalion, and the Metalion will not be harmed. Contact with any non-destroyable portion of the stage is still deadly. During the effects of this power-up, the Force Field shield will not be displayed.