Over 10 years ago, I used to play a game called Oxyd. It was a terrific puzzle game that involved rolling a marble though different maze-like levels and, essentially, playing the game "concentration". You pushed the marble against certain blocks and they revealed colored dots. These blocks came in pairs, and you needed to activate them in pairs. For instance, a level might have two pairs of these blocks -- 2 red and 2 blue blocks. You would need to push your marble against these blocks in either blue, blue, red, red or red, red, blue, blue sequence. If you activated a red, then hit a blue, the first red block you hit deactivated. It was much simpler than I'm describing it. It's just like the kid's card game "concentration", except you roll this marble around. The landscapes could be extremely challenging: various surfaces and hazards, reversed controls, objects to use, blocks to push around in the right way, etc.
It was a great and addictive game that proved that games can be great without fancy hardware effects or 3D.
Anyhow, I just found out that it has been ported to various linuxes, OS X as well as Windoze as a game called
Enigma. This clone of Oxyd has over 500 levels! I am so happy to be able to play Oxyd again! I've tried to describe this game to people, but I've never been able to explain how cool it was.
Those of you who like puzzle/patience games might want check it out. Its freeware.
Jim