banger music and the sfx add to the feeling that you're in some sort of cave. always appreciate it when tutorials are integrated into the game and not just blurbs of text before you start playing :) fun core mechanic that could def be expanded upon.
apart from the collision stuff other people already mentioned, i think you may have forgotten to set the music to loop? cause it would stop playing for me at certain points during levels. or maybe that's not a bug!
great entry!