Really cool puzzle mechanics that, in turn, created really cool puzzles. The last two puzzles had me scratching my head before I figured them out. Lots of great revelation moments.
My only (minor) complaint with the mechanics is that I never figured out how the game determines which block to swap to if you have two or more blocks in your radius. (This was a problem we had to figure out for our game, which has a similar mechanic.)
I had a fun time with this game. I just wish there were more puzzles. Great work!