That was great. The concept seems super simple at first but you get some really interesting puzzles later on.
One suggestion is to not perform repeated actions when the user holds the movement keys. Quite often I fell off the map. I think having to release the button before being allowed to input another move works better for these kind of grid games.
The game is really good, I think you could make a full version out of it at some point!
Congrats on shipping!