Unfortunately, it's only a demo version. It says that it's 70% of the final product, but I think that it's only about 35-40% of the final product. The game is very limited, only a few options being available. Anyway, the game moves perfectly of my MacBook White (2.0 GHz, 2GB of RAM and nVIDIA 9400M).
But, avoid playing continuously for hours. The game pushes the fan to high speeds from the first minutes of playing, so it will put a real stress on cooling system if you play it for hours.
More details and download here: http://www.apple.com/downloads/macosx/games/demos_updates/colinmcraerallymac.html