Just tried the rather obscure game Normality on my 1.67 Powerbook, took a right load of fafing about to get it installed as it kept crashing and freezing the whole computer, but anyway, got it installed

works ok, but I did have to drop down to low detail or else the movement was a bit jerky, check out this video, (skip the first 5 minutes) to see the 3d environment of the game.

http://www.youtube.com/watch?v=lkcfNV-jkaY