Push DX is a Sokoban type game, with lot's of additional features, including 4 different block colours, icey floors, holes, and more. The game also includes a level editor so you can design your own puzzles.
To complete each level you must push all of the coloured blocks onto the same coloured floor tiles. Blocks can only be pushed and not pulled, so care must be taken or you may end up stuck.
Full instructions for the game and level editor are included with the download.