Crysis 2 what is god mode?

Answer 1

God mode in Crysis 2 prevents the player from taking damage or dying.

Answer 2

The term GOD mode is not exclusive to Cysis 2 alone.

In fact Crysis 2 is continuing the tradition of calling invincible mode in FPS  as GOD mode from the very first FPS which revolutionized the FPS genre. And that is DOOM.