So many games incorporate it now, it's the new standard. I agree with the credit given to GoW here, used very well to create a fluid system messed up so completly in numerous other titles. I like the cover system used in Hitman Absolution, they managed to add this simple mechanic to make the game more action orientated which to be honest isn't as cool as Blood Money for my liking but none the less it's an insanely cool game.