At some point, I earned a free copy from The India Gala. Not sure when or how, but I'll take it. It's a voxle (sp?) based FPS. So, the environment is not static. Your grenades and bullets will break walls, the floor, etc. You can even equip a shovel and dig new tunnels and corridors. I was watching a stream, and the graphics (all blocky) are awkward. But it was cool watching them shoot a wall apart trying to get a shot on their enemy. Watched another guy go into a tunnel and catch a guy digging. Then he had to dig himself out.
Interesting concept, I thought. I would like it even better if as you got shot, you lost body parts. Get shot in the arm, your arm falls off. Pistols only for you. Shot in the leg, down to one leg. Walking speed and no jumping. Etc. But I don't think that was happening.