Heavy Rain for the PS3 is all about the coices you make. You end up playing as 4 different characters throughout the game, and if you are careless, some of them will die. The game auto-saves though, so you are forced to continue playing to see the outcome that you have created. It give you quite a bit of those "aww crap! I should have done that differently!" moments.

The Source SDK thats they used to develop the game is not available for OSX yet. Once Valve releases the SDK for OSX, I'm sure you'll see the game on the mac.