Gal's Dungeon is an adult unlicensed Famicom Disk System game by Super Pig. You play as private eye Kogorou Kurachi, tasked with rescuing the daughter of a crime syndicate boss from the mysterious "Phantom of 40 Faces". It's a 3D dungeon game, similar to the mazes in Wizardry and other terrible computer RPGs, where you progress through eight floors of …

An adult version of the classic arcade game Space Invaders which upon beating levels you get to see various girls undress.

An unlicensed hentai game that's basically solo table tennis where you hit certain parts of a wall to reveal a girl in an erotic pose.