Wrap your mind around the next intensive puzzle game - Interlocked!
A 3D puzzle game with a chilling atmosphere.

You know those puzzles consisting of a few wooden blocks that are impossible take apart? Then you know Interlocked.
Each level, you’re given a unique 3D puzzle consisting of blocks
that hold each other together.
Take it apart and you'll feel ten times as smart :-)

official Website

just to see how hard this stuff really is:



Simple?
You wish.

This is a pretty fun game, although I really suck at it and only got to like lvl 5, until I got too lazy and stopped playing.