Neat game. Would be cool if once you beat a level you could get the 'solution' which would make the level sound decent, instead of the cacophony of noise that you get if you beat the level by 'accident'.
I think the most irritating thing about this game is dying while you are "leveling up". You shouldn't explode when you are airborne, if you run out of fuel during a 50 kill combo, you shouldn't be penalized. Also, if you get enough experience for the next level, you shouldn't explode waiting for your experience bar to count up the points.
NoxAeternus' comments