I'm glad you liked it, especially the sounds- puzzlescript doesn't have full audio support, just a random sound generator, so it can be tricky to get things sounding just right. As for level design, I've been playing block pushing games on puzzlescript.net for years, so I guess I've picked up a few tricks- although to be fair some of the earlier levels in my game are mostly crate spam to simulate actual difficulty :P When I had more time to work on levels after the jam, they got a lot better and more interesting, and I'm still coming up with new concepts and mechanics.
The undo feature is built into puzzlescript as well! It's a very powerful framework for a very specific kind of game, so if you like turn-based puzzlers I'd definitely recommend trying it out.