The Maze of Galious (魔城伝説II ガリウスの迷宮 Majō Densetsu Tsū: Gariusu no Meikyū?), is the sequel to Konami's MSX game Knightmare. While the first game was an overhead, vertical scrolling shooter, The Maze of Galious is a side-view, flick-screen platform game. The player controls Popolon and Aphrodite, entering the evil priest Galious' castle to free their yet-to-be-born son Pampas from the priest's evil clutches. Being able to control Popolon and Aphrodite means the player can switch between two characters that have slightly different abilities. For example, Popolon can push stones and open heavy doors. On the other hand, Aphrodite survives longer under water and she can shoot more projectiles. Should either character die, the other can visit a shrine and pay for resurrection. Unlike typical platform games, both characters can survive some damage as they have hit point bars.
The game has several types of enemies, each with strengths and weaknesses. Some monsters are immune to frontal attacks, some are more vulnerable to fire and so on. Ten different bosses are to be fought too. Defeating a boss will give the player a key that is used to unlock doors to other boss areas. In-game saving is provided by giving player an encoded password.