Use the arrow keys to move. Avoid red things, or you will loose health. Hit into the enemy with a sword to hurt it, and when you defeat it, you get health back. Click the pink two-player Icon to summon in the pink player, controlled with wasd keys. In two player mode, if you die you turn into a ghost. While a ghost, you can cheer on other player! Space for blue, [q] for pink. The arena is randomized each time you press the flag.
The coding is by me, the drawing is by me (bitmap), and the music is from Undertale.