Planned Release Date: 2025

About This Game

Invite up to five friends and operate your submarine. Together or alone.

Navigate carefully and consider every move while you progress through one of 20 challenging and unique cave systems in this slow pace, atmospheric diving experience. Reach the target location without crushing your submarine into the walls by operating your cameras, ping and the submarine's movement. Together or alone. While you can operate the submarine all by yourself - It’s way more effective to have a few helping hands on board. So hire your friends who are up for a dive experience.

It’s simple. Maneuver your submarine to collect the target and return to your base while not scratching the cave-walls.

You will be spending 95% in the submarine. You (and your friends) can freely move within it and by operating the submarine's consoles, you can move and navigate your submarine. Dive through challenging cave systems by turning, tilting, rotating and adjusting movement speed, without touching the walls.

If your submarine touches the walls too often, it will sink and the dive failed. The challenge here is that you only have limited tools to see or hear your location within the cave. There is always a target at the end of the cave that you need to reach and return to your base with.

With every new launch or restart of the game, one of 20 caves will be chosen randomly for you to play (more to come). Think of it as some kind of hot-wire mechanic. In a sub. In a cave.


A charming "I am not an submarine expert but I want to maneuver a submarine with my friends but without the torpedo and war stuff going on but only for around one hour per dive" experience.

This project was designed to be a slow pace, multiplayer experience to play with friends while chatting in your favorite voice-chat. You can even play this game with mouse only, so you got one free hand for your favorite cup of tee, or coffee.

As you progress further with a successful mission-line, enjoy new ranks, new uniforms, some beards, and some new cups for your character.

Important to notice:
- Only steam friends can be invited. There are no open server selections.
- "Sub Optimal Co." uses peer-to-peer connection.
- There is no ingame voice or text chat.
- No bots or NPCs can be added to the party.

It‘s a small game. It‘s a simple game. It‘s A Sidegame.