As others, I strongly recommend adding at least some form of audio; background music doesn't take long to add if you know where to search, and it can improve the experience by leaps and bounds.
Other than that, there's some decent platforming prototype going on, but very little content (at least the game wasn't packed with lots of levels featuring way too little variety). I think there's some room for improvement as far as game feel goes; maybe some knockbacks and/or player's actually moving during attacks, so that the combat doesn't feel "stiff"?