You buy Barotrauma.

Region: Russia and CIS

Overcome all the gravity and inexorable pressure of a frozen ocean. In the not very distant future, habitable places became quite small, so people went to the satellite of Jupiter. On the frozen surface of Europe, conditions are extremely harsh, so people form small habitats in the dark depths of the ocean under the ice. But this is not the only form of life that can be found there.

Play with friends in an exciting multiplayer mode, explore the frozen depths of Europe in a single-player game, and change the game with the help of fully integrated modification tools and the Steam workshop. Procedurally generated levels ensure that each next game will be different from the previous one.
Features
Play as a submarine captain, engineer, mechanic, doctor or assistant. Help comrades to survive or make sure that no one survives.
Manage the many onboard systems of your submarine: nuclear reactors, sonar, weapons, engines, and more.
Create tools, drugs and weapons with an integrated manufacturing system.
Explore dangerous places, fight with creatures that you meet on your way, or run away from them.
Explore alien ruins and broken submarines in search of rare and strong artifacts and resources.
Realize your creative potential with the help of the submarine editor, character editor and procedurally generated animation editor. Find mods and share them directly in the Steam workshop.