Deep Submarine Odyssey is a 3D mobile game set on the same Kappa planet of the Galaxy on Fire universe by the same developer. It takes place underwater. The player controls a submarine that can freely explore a large environment. There are stations to visit, upgrades to earn as well as new ships, resources to collect, goods to craft and pirates to fight using shooting mechanics from a behind view. After completing all the story missions, you can continue playing in an open world environment where trading is made available as a new gameplay element.