short fun game. I really liked it and it has a lot of potential. Can't wait for the full version!
Suggestions:
Def make it a lot harder I think it would be more exciting. Falling into a hole should have bigger consequences. Perhaps make it do % oxygen damage, like 10%.
Maybe make rock depletion faster after losing all oxygen. From the end to the beginning I only lost 120 of my 600 rocks. Enemies should give less rocks, right now its way too much. Also I feel like breaking rocks to give back oxygen is too frequent.
Also the light should do something other than give vision I think since i kept it level 1 for the entire demo