Plot: The Nightmare of Druaga: Fushigi no Dungeon is a roguelike video game developed by Arika, Matrix Software, and Chunsoft, published in 2004 in Japan by Arika and in North America by Namco Hometek exclusively for the PlayStation 2. Wikipedia
Plot: The Quest of Ki is a 1988 video game developed by Game Studio and published by Namco for the Family Computer. It is the third game in Babylonian Castle Saga series which started with the 1984 arcade game, The Tower of Druaga. Wikipedia
Plot: The Return of Ishtar is an action role-playing arcade game released by Namco in 1986. It runs on Namco System 86 hardware and is the sequel to The Tower of Druaga, which was released two years earlier. Wikipedia