This game is great in concept, but there are a few issues (one being that I am by myself and can't actually have a cohesive fight). Due to the up and down arrow keys being bound to attack and jump for the red player, the attack seems to get stuck since the page scrolls when these are pressed. Also, the audio when getting hit and attacking seem to be a little inconsistent and sound slightly delayed. The players can also jump indefinitely in mid-air, allowing them to jump off screen. Other than those issues, your game has potential to be a fun experience with a friend by your side.