The moss in the first picture makes me pretty sure that's not real life. It doesn't look right, and its placement seems somewhat questionable.
The second pic takes more careful consideration, but if you look at the water it looks like Crysis's water and there are also some unnatural green spots in the lower right. My first tip was the fact that I couldn't spot any loose leaves of the type seen connected together like a string of fire crackers. Oh, and the green thing sticking out of the water almost looks photo shopped in.
The third is harder. I didn't look as long , but nothing immediately said to me that the pic was fake. It could be real, but I'm still doubting it.
Anyway, without careful inspection all of those pics look pretty realistic. If they were just pics I randomly looked at (as opposed to being told "Crysis looks so real" first) I might not catch on. The first would still make me think twice, though. That mo9ss just really seems wrong to me.