Ineteresting game.
Graphics: Pretty bad. Did I way pretty bad? I meant extremely bad.
Style: Good idea for a game. Badly executed. No plot. No instructions of what you have to do.
Sound: I guess the music was alright. But you should've had sound effects. One for jumping and one for finishing the level at least.
Interacticity: Meh. You should be able to control how high the guy goes by how long you hold the key down, instead of one single uniform height. Also, you should have the ability to hold down another key and press right or left with it being taken into effect. Oh, and a barrier wo you don't jump off the screen.
Try again, with better everything.