i like gmod like 3d games for mac (i cant find any for mac tho D: )
anyone play Blockland? go download it here! http://www.blockland.us/index.asp
even if you need to buy a key to play the full version, there is a hack,
enter this -Snip-
No, you only need one source engine game. It could be just HL2, just CSS or any other game, though i recommend that gmod is bought with the orange box, as the orange box may just be the best game deal ever.