Sticky Blocks™ is probably the most original new idea in the block sliding puzzle genre for a decade. Unlike Move it!™, where the puzzle is always still solvable, no matter what moves you have made, in Sticky Blocks™ a bad Sticky Join may have made the puzzle completely insoluble. Now you have to think more carefully whether the join planned is fatal or not. However you cannot just avoid all sticky joins as almost all puzzles demand that you make at least one such join. Some joins will allow the puzzle to be solved more quickly as they allow the joined pieces to move as one piece, so can move more quickly.
This puzzle needs more thought than the conventional block slider and can be much more challenging.