The latest Crysis video walkthrough shows that CryTek have not just been working on the flashy graphics but also on a lot of finer details. Animals will feature heavily as a graphical feature, complete with extremely realistic behaviour. Different types of fish in the water look and behave as they would in real life, chickens don't move and flock the same way as other birds.
Embedded + Downloadable HD:
Part 1
Part 2
Part 3
