Cool game, the controls seem pretty unique and the sprites are nice!
It might be a good idea to lower how quickly you rise / fall, as currently it's pretty hard to get yourself into the right position, also I'm not sure whether this was a bug or you simply haven't developed that far into the game yet, but upon killing all the enemies you never seem to progress into wave 2 as the UI would suggest. If the latter it may be a good idea to simply remove the wave counter to avoid confusion.
Great work!