Games follow a completely different modeling methodology.  Every single model in crysis is optimized polygon wise.  When downloading assets for Vue/Poser  you can easily download an object with 50,000 poly's, where in crysis the same object would only be 300-400 poly's, plus normal mapping, plus displacement maybe and you got a low poly object that looks exactly like a high poly object.

There are a lot of modelers out there who get too crazy with meshsmooth & turbosmooth, making objects have more poly's than they need.

Zanzo