I can't say I agree with the decision to kick the player back a level to "prove their skill" when success in the game is in no small part based on luck. It doesn't feel frustrating but fair, it just feels frustrating (that said, I could behind it if there were a way to die on Level 0 -- just introduce Death Mode into the array of glitches that can be served on the first level -- and get to "glitch" levels like Level -1).
That said, your use of sound and visuals are impeccable. Excellent work there. With some mechanical polish I think you'll have a stupendous game.