Use the WASD keys to move, and the space bar to shoot. The sniper shoots one projectile that deals high damage, the AR shoots lots of weak projectiles, the shotgun fires a bunch of shots in a spread, the crossbow fires one high pierce and damage projectile, the sword attacks in a semicircle swing, and the bow fires like the sniper, but towards the mouse.
Credits to: Me, for making the game Metroid and Undertale, for the music