[Batisphere] It unfolds in a cramped diving hole in the deep sea. Horror strategy adventure game The protagonist came down here to find a lost person.

 A turn-based strategy death game set in the deep sea

First, hide yourself in the underwater terrain. Then, exchange detection pulses with the opposing submarines and use the information they return to pinpoint their location. Only the first to destroy them will survive.

 Mysterious facility and time loop

What on earth happened here? Slowly broaden your horizons with insights gleaned from failure and information gleaned from bizarre facilities. Everything starts from scratch, but it's not just knowledge.

 Analog Exploration in the 1940s

The Bathysphere is filled with unique analog equipment and tributary documents. Tune in to the radio and read the manuals. Hidden secrets await you, transcending time.