You are the Green cube at the bottom
You can control this cube using the arrow keys. The game will rotate but the arrow keys will always move the cube relative to you, not the game (will make sense when you play)
Your goal is to shoot the falling Blue cubes before they touch the bottom
You can shoot by pushing the space key
Occasionally, a Green cube will fall, shooting this cube is optional, but doing so will grant you a temporary laser beam (which is kinda OP)
You can also use the mouse to zoom (by scrolling) and rotate (click & drag)