Nice game! I love the style of mashing keys to win.
Music was cool, art was cool, I wish there was more to the game though. Maybe a boss or different characters. Also, the AI could do for some more skill, the AI when the lighter character was very weak, and the AI when the darker character was slightly better, but still couldn't handle my mash ability.
Luckily I figured out that IJKL would work for attacks, but sadly no info on this in the description, and there are probably more buttons for attacking.
Other than that I think this game has a lot of potential, and the polish is already decently there. Nice work.