It was really fun to play but IMO there was a huge difficulty spike between 1st and 2nd levels. Also the first level took me around 5 retries to crack. I'd personally pad these levels with more simple ones where you introduce gate/loop/lever/box mechanics separately, and then let them play the levels you've made. Don't get me wrong, it's a good puzzle game, it gave me some "a-ha" moments, but I believe the difficulty needs some balance.
Good work overall!