Detonator Orgun is a menu-driven adventure game developed and published by HOT-B for the Japanese Mega-CD. It was never localized or released outside of Japan.
It is based on the three-part series of OVAs of the same name, first released in 1991, which follows college student Tomoru Shindo as he comes into telepathic contact with a being named Orgun: a defector from a race of warlike bio-mechanical aliens collectively known as the Evoluder, who have been carving a path of destruction across the cosmos. With their eyes set on Earth next, Shindo, Orgun, and the Earth Defense Force must prepare themselves for battle.
The game uses a standard format for Japanese adventure games at the time: the player is given a list of commands they can perform in the vicinity, and by activating the right ones in the right order they can progress to the next scene. The game closely follows the events of the OVAs.