Enigma (Puzzle Game)

I found this unique and addicting puzzle game called Enigma, which is based on Oxyd (if anybody has ever heard of it), and it's open source.

Here's the description from their web site:

Enigma is a puzzle game inspired by Oxyd on the Atari ST and Rock'n'Roll on the Amiga. The object of the game is to find uncover pairs of identically colored Oxyd stones. Simple? Yes. Easy? Certainly not! Hidden traps, vast mazes, laser beams, and, most of all, countless hairy puzzles usually block your direct way to the Oxyd stones

http://www.nongnu.org/enigma/index.html