Ganpuru: Gunman's Proof

Ganpuru: Gunman's Proof is set in a Wild West town on a small island in 1880. The arrival of two meteors precedes a series of monster attacks, each marked by a mysterious crest. A young local boy becomes the vessel for an alien space sheriff named Zero, who explains that an escaped intergalactic criminal called Demi is responsible for the chaos.

Gameplay involves real-time combat against numerous enemies within dungeon-like environments. Instead of medieval weaponry, the arsenal consists of firearms like pistols, a shotgun, a machine gun, and a flamethrower, all of which have unlimited ammunition. Defensive maneuvers such as ducking are available, and special attacks can be executed with different weapons.

The experience incorporates light role-playing elements, primarily through the acquisition and enhancement of weapons. The player's objective, directed by the possessing alien, is to locate and defeat Demi to restore peace both to the island and to the alien world.