Revealed at Space World 1999, it was being developed by SETA Corporation as a turn-based strategy game, very similar to Nintendo's Wars series, but with a realistic setting. This game would have supported 4-player online battles using the Disk Drive's Randnet service. The game was delayed multiple times and eventually changed format to a cartridge. The change in format led to the removal of the online mode, and ultimately, Ultimate War was cancelled altogether.