Deep See, a VR game.

Here is a concept art of the game’s environment. 

Most of the planet's oceans are very dark.  At a depth of 150 meters (approx. 500 feet), there is little if any light left, and colors are no longer visible to the human eye.  As odd as it may seem, we know more about outer space than we do about the deep oceans of our own planet.

marianatrench.com 

Deep in there, you wont be alone... Creatures are lurking in the shadows. Here is a concept of the creatures you are going to encounter during the game. 

What is Deep See

Deep See is a Virtual Reality game that sets in the deepest crevasse of the Marianna Trench. You impersonate an engineer sent to prepare the environment of the deepest ocean for immediate colonization. The sun shat down, and the coldest temperatures were felt. Our only option to survive is to go deep, as close to the center of planet Earth as possible. 

Deep See.