This seems really cool so far, and has some pretty interesting puzzles! As someone who plays a lot of puzzle games, I do have a few suggestions, whether for this or future puzzles games:
- Add an undo stack and try to make it as snappy as possible (ie holding down Z should rewind your moves at increasing speed). Complex levels are much more fun when a dead-end solution or a misclick doesn't force you to start from scratch, especially when the mechanics produce a lot of fail-states. (Including level restarts in the undo stack is also a good idea).
- Add a level select. The later levels are complicated enough that I don't know that people will tackle this all in one sitting. The other advantage of a level select — or overworld if you're feeling really ambitious — is that you can introduce some degree of non-linear progress. So if a player gets stuck on one level, it doesn't result in them bouncing off the game entirely.
- I'd consider allowing the player to rotate the view by clicking and dragging on non-interactable surfaces. This is largely because I'm playing on a Mac where a right click is a two fingered click, which is can accidentally turn into a scroll/zoom — more importantly though, there's no reason you couldn't port this to mobile if you got rid of the right click limitation.
- I like the minimalist look, but the black blocks start to feel a bit oppressive on the larger levels.