100% photogrammetry i.e. the textures are taken from photographs of the real world rather than created from scratch. That is not a criticism, it works really well, I expect we'll see much more of this technique in games in the coming years.
The lighting is very good but not quite 100% photorealistic.
Where it falls down (in that video at least) are the textures and movements used for the player's hands and gun. But that's something they can easily improve on.
If there are decent reviews regarding the gameplay I'll certainly be purchasing this, looks fun.
I wonder what the GPU requirements will be like though?