I don't know if you are familiar with Starbound, but it has a really nice camera system which lets you hold a button and move camera off centre while still keeping the character on screen e.g if you know you are going to be moving to the right, you can move the cam so that the character would at far left side of the screen. I am not sure if it would be possible for you to implement something like that with how you move and rotate the camera sometimes, but I think it would be a nice addition to the game.
the three skeletons
oh, I completely forgot about your skelly boys.
Definitely should make the non-dangerous lavafalls in the background be a more desaturated color so people don't think it will kill them.
I feel like everything in your game tries to kill the player, so don't be surprised when players try to either play very carefully and get scared of everything, or they get tilted hard and try to rush with using the time power over and over even for easier sections.
big electro robot
yes, he really needs better artificial intelligence.