Use A & D to move left and right. Use W to jump and S to crouch. Use Q to dash and E to switch weapons. Hold space to shoot. The number in the top left is you health and right next to it is your DPS. The difficulty gauges how hard the game will be.
Inspired by Cuphead (if you didn't notice). Difficulty 4 is barely possible, but I have beat it before so give it a try... if you dare.
