Very well polished game. Overall everything was really well done. I only have 4 points that I feel were underdeveloped. Lasers hurting enemies but spikes not activating or hurting enemies feels disjointed. The coins feel very meaningless, and since there is a ton of them and they reset on death at some point I just stopped caring about them. Having no option to regain HP back incentivizes players to kill themselves as they regain their HP back and the coins are meaningless. Finally to even more incentivize player death once you get a crystal piece you have to trek all the way back. Or you can just die and get there faster.
The coins here are the real Achilles heel as having them have a purpose would help 2 of the other issues. Otherwise very nice game. Good job!