hi, i just decided to buy this game ... then i saw that it still at 50 bucks in steam .. but its availible for 30 at amazon

at amazon it says that i require steam to be able to play the game anyway ... so that means the amazon version comes with full steam support? .. steam achievments, steamcloud etc? .. can anyone confirm that? cuz i hate games without achievments ^^; and i love the steam achievments

usualy i buy games only at steam ... so may someone can give a quick response plz?

Yes, the retail version registers on Steam and you'll have access to all its features.