CONTROLS Move: WASD/Arrow Keys Aim: Mouse Shoot: Space/Mouse Button (Can be held down) Press V in the main menu to change the volume OTHER The counter on the bottom left is your shield points The spinny pink thing that appears mid-game is a shield pickup The only differences between the difficulties are damage dealt and invulnerability frames
Thanks to the beloved @Penguinsareus for the original game. I basically did nothing except I pixelized it.