Really cool mechanic and visual design! I was worried with the drawing that it would be unreliable, but I never ran into any problems.
I do wish the attacks had more weight and that bones recovered faster. In the room where I need to hammer down the buttons I was able to go get water and come back before the bar recharged. Perhaps holding space could let you retract your spent bones or after using an ability your attack bursts into bones to quickly recover your bar.
I really enjoyed this game, seems worth carrying on with if you enjoyed making it!
Good job!