Crysis 1 and Crysis Warhead were both linear. Each were like...well basically, using a coreographed sandbox for each level, except the levels were big and the way how Crytek could make Crysis 1 was like this: "Okay we got a few trees. To place a tree in the game, we press right mouse button. *Holds right mouse button and drags it across the whole level.* K, im done with this level
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With Crysis 2, Crytek made it this way: "Okay, we got that building model. Place it here and here. Then we got THAT building model...place it here and here. We got these so many posters to put all over the place. Oh yeah, don't forget we got a bar to make with glasses....and some trucks and..." You see the point im making?
Also, we don't know if the DLC is free or not. Nooooobs lol.