PuzzleScript is a new (1 week old yesterday!) engine for writing tiled, turn-based puzzle games.
It seemed perfect for a writing version of an old Gameboy game called Catrap, so I started yesterday and finished today. Most of the time was spent defining the levels - the game rules are only 11 lines!
Feel free to try it here.
Update: Thanks to Alan Hazelden, pushing boulders is now a bit smoother.
Update 2: Fixed level 40 so it's now completable.