The series is mainly based on the popular King of Fighters franchise by SNK Playmore and features both characters and stages from the series and originally. made by Zelgadis with the 2D freeware engine M.U.G.E.N. A promotional picture for The King of Fighters Memorial. The series was developed originally for SNK's Neo Geo MVS arcade hardware. The King of Fighters Memorial (often at times shortened to KoF Memorial or abbreviated as KoFM) is a series of fan-games.