This is really nice! The levels were challenging and sometimes intimidating at first, but I never felt like they were obtuse or frustrating.
There were couple levels that I solved without engaging much with some of the blocks. I wasn't sure if the extra blocks were just decoys, or if I found an unintended solution.
The combination of enemies and switches creates some fun problems. I like that the enemy won't move if you can't move, which means you have to think through the timing if need them to be hitting switches for you.
I had to stop at level 17, but I'd like to come back. How many levels are there?