The Earth is divided into three main powers: the free world, the communist block, and the New Communist Federation. A program to denuclearize was supported by all three powers, which led to the development of a devastating non-nuclear weapon called Psy-O-Blade 's satellite counterpart. The danger of total annihilation returns as the other two powers develop their own killer satellites. Humans abandon Earth and colonize other planets in an attempt to survive. In the 22nd century, humans send an experimental ship called SSeptemius 1 to a star six light years away from the Solar System.
The player takes on the role of Keith McDonnell, a 17-year-old crew member of the ship SSeptemius 2 , who is sent to investigate the disappearance of the SSeptemius 1 's main computer. The game Psy-O-Blade is a Japanese adventure in anime style, where the player interacts with the game world by moving a cursor and clicking on objects or people to examine them or talk to them.
The gameplay involves moving the character around, visiting different locations, examining objects, and talking to characters. There are no puzzles to solve, and the player advances in the game by completing these interactions. The player's goal is to progress through the story while exploring the world and interacting with the characters.