Great little puzzle game you've got there. Looks really great, the puzzles themselves are good and the progression of difficulty is quite nicely balanced. I was a bit confused by the second level until I'd skipped it and used the teleports on a later level (I didn't really get what it was until later), but other than that you got everything across without having to explicitly say much, which definitely added to the aesthetic.
If you're going to put a bit more time into this, I'd love to see some subtle animations on those cubes (something like snakebird), an undo last move button/key would be fantastic (that last level got a little annoyingly repetitive, having to go all the way back to the start by mucking up the correct movement path), and yeah, some sound/music would really bump up a lovely game