Very fun game! I respect a game that has a specific goal and executes it well. The puzzles are satisfying, and the environs are just as detailed as they need to be.
I like the difficulty of the puzzles. The harder puzzles were tough enough to make me scratch my head, but not so tough that I needed to phone a friend. Some were very easy, but I could tell they were there to teach me a mechanic, so I stayed interested (and got a pleasant break from the difficulty). The way they build on each other reminds me of Mario games.
It brought a smile to my face on a hard day.