This is an awesome Sokoban-style game! It reminds me of a lot of the games made with PuzzleScript.
It was quite challenging, but I always enjoy a good brain-scratcher. I had to watch the video on the start of level 4 just to make sure I wasn't missing anything, but after that I was able to complete all the levels on my own (although it took awhile XD).
I also like how you did the level discovery portion - I wanted to do something similar with my game but it ended up being confusing so I left it out. Yours worked out great though! Thanks for the awesome game!