The one level where you get Rook. you can soft-block yourself in the middle by falling and not get back up. almost forgot you can press R to reset.. Maybe show controls in some corner or something.. You could make the gameplay little easier by not needing to click on the chess-piece before moving it.(but yeah, there is a reason after all for this in one of the levels.) Some levels it's hard to see further ahead. maybe make the camera move with the mouse or draggable so can see more of the play area ahead or have the full level visible in the camera space and camera locked in place. anyway good puzzles. great job!