First click the board. Twelve polysquare tiles will drop.
If not all polysquares fit onto the board, the message 'Stalemate: I lose' will appear. In this case, go back and click the empty board again.

Your task is to assemble the given polysquares into the square puzzle like the one given on the right half of the board.
You cannot lift the polysquares off the board; hence they are obstacles for each other's movements.
The polysquares can only move horizontally and vertically and block each other exactly as physical tiles would do.
You cannot rotate a polysquare.

The sweet spot (handle) of each polysquare is marked.

You win when you exactly have achieved the position shown at right, with the assembled square in the center of the board.

Random Variants:
There are 9 variants with random setups. They differ in the number of blocking tiles dropped.
Some random setups with lots of blocking tiles might not be solvable.

Fixed Variants:
There are also 14 variants with fixed setups.
Some variants have additional blocks to make moving the polysquares more difficult. Of course, the more blocks are on the board, the more difficult the puzzle is and the more moves are necessary to solve it.
All fixed variants have solutions, which are attached.

Please note there are 20 alternative piece sets available.