Amazing, just amazing! If anyone ever doubts how important is music to a game, show them this game. Everything is very polished, and the simple structure is just incredibly effective, everything just fits together! I think if you added a high scores list with names in a save file or something, you could easily put it as is in an arcade. If I am to point negatives, I think I would say it gets old eventually, it's the kind of game that you play once for a couple of minutes, get your high score and never turns on again. If you were to add more variety, multiplayer and some other forms of challenges it could be better, but now that I think about it, wtf am I talking, this is a game jam!!! So yeah, I think this is a complete prototype, congratulations my friend!!
PS: I got to a point where I giant dude dropped on me out of nowhere to kill me. Did this happen always when the player gets to 8k?
EDIT: Solid 5 on gameplay and audio for you =)