Sokoban 3D is a 3D version of the puzzle game sokoban. Its goal is to push crates into marked positions. Sokoban 3D has got many features, like full camera freedom, cool graphics, many levels (you can add levels too), unlimited undo and redo, and pathfinding.

Furthermore, Sokoban 3D is completely free and open-source! You can download the code here: http://cvs.codeyard.net/svn/Sokoban3D/source/