I found an error in the snapping algorithm for the "Key" level (level 23). If you snap the parts that form the upper part of the bow before you finish the bottom part, you will be unable to fit the triangular piece, and therefore be unable to finish the puzzle without resetting.
All in all, fun concept, albeit quite easy. This would potentially be a good game to transfer to a touch interface and targeted towards young children.
 "Shape Fold 2"){kind=icon}
 "Astroflux"){kind=icon}