Ambient Occlusion
 

Not technically an 'issue'; Any Idea if this game supports Ambient Occlusion?
Can be enabled in gaming profiles in the nvidia drivers I just noticed. Most other games this option is greyed out but Cryostasis it allows me to set it...

Is suppose to improve visual quality slightly improving way light interacts or something, but also potentially reduce performance. Just tried it on but have to admit I can't tell any difference in visuals or performance.

If you're not seeing a nasty performance impact then it's not on. I don't think there's any way to enable it right now, and even if NVIDIA enables it in a future driver version, I'd hate to see the framerates with it on ;)

Diffuse lighting has a feature in it which has a very simple AO effect. You can turn that on in config.cfg.