Knightmare is a 1986 vertically scrolling shooter video game developed and published by Konami for the MSX home computer. It was included in compilations for the MSX, PlayStation and Sega Saturn, followed by a port for mobile phones, and digital re-releases for the Virtual Console and Microsoft Windows. It is the first entry in the Knightmare trilogy. The game stars Popolon, a warrior who embarks on a quest to rescue the princess Aphrodite from the evil priest Hudnos. The player must fight waves of enemies while avoiding collision with their projectiles and obstacles along the way, and facing against bosses.

The Maze of Galious is a 1987 platform-adventure video game developed and published by Konami for the MSX home computer. A reworked conversion was released for the Family Computer. Both versions were re-released digitally for Microsoft Windows. The second entry in the Knightmare trilogy, it follows the respective hero and former damsel in distress of the previous game, Popolon and Aphrodite, as they embark on a journey through Castle Greek to free their unborn child Pampas from the evil priest Galious. The player explores each map in search for items and power-ups to progress, while also fighting enemies and bosses.