A list of basic controls and some tips for those new to the game.
Default Controls: B jumps - If pressed while ducking, goes into a morph ball-like form that always moves until you jump again. Y fires your primary weapon - Holding it will rapid-fire, which can be disabled in the options menu. A or R uses a smart bomb (called "Line" in the game's options menu) - Sends out two shockwave lines from either side of you that deal a large amount of damage, enough to instantly kill most of the weaker enemies in the game. X or L fires a taser beam - Can be aimed using the d-pad left or right.
Weapons: Weapons can be upgraded a number of times based on how many of the same color you collect, and weapon strength persists even if you pick up a different weapon. Dying loses a level of strength.
Red: Spread Shot Starter weapon. Fires faster if you spam the fire button rather than hold it.
Level 1 - Fires a bullet straight forward. Level 2 - Fires three lines of bullets in a cone. Level 3 - Fires six lines of bullets in a cone, split into three waves of two bullets each. Level 4 - Fires nine lines of bullets in a cone, split into one wave of three bullets, two waves of two bullets each, and two waves of one bullet each. Level 5 - Fires thirteen lines of bullets in a cone, split into three waves of three bullets each and two waves of two bullets each.
Blue: Laser Shot Rapid-fires very very quickly, but individual shot damage is somewhat low.
Level 1- Fires a laser shot straight forward. Level 2 - Fires a barrage of one large and two small laser shots straight forward. Level 3 - Fires a barrage of three large laser shots straight forward. Level 4 - Fires a barrage of three large and two small laser shots straight forward.
Yellow: Rebound Shot Shots split-rebound off of walls at opposite angles and deal less damage than the direct shot.
Level 1 - Medium orbs split into small orbs that do not bounce off of walls. Level 2 - Medium orbs split into small orbs that bounce once. Level 3 - Large orbs split into medium orbs that bounce twice. Level 4 - Large orbs split into medium orbs that then split into small orbs that bounce twice.
Pickups: Diamond: Adds 100 points to your score. [Orange gem that flashes] Life: Gives you a 1up and adds 500 points to your score. [Miniature Turrican] Smart Bomb: Gives you an extra smart bomb. Despite the GUI only displaying 3, you can hold more. [Glowing blue pickup box] Power Up: Restores all your health. [Glowing heart pickup box] Shield: Gives you invulnerability for a short time. [Glowing green pickup box]