SD The Great Battle, from Super Famicon (japanese SNES), is a platform game with aerial view originally released by Banpresto and Namco Bandai Games (formerly Bandai) exclusively in Japan that began in 1990 and is a part of The Compati Hero Series (in japanese "Konpachi Hiro Shirizu") that serves as crossover between ULTRAMAN, KAMEN RIDER (also known as Masked Rider) and GUNDAM.
It was the first video game series to involve a crossover between animated giant robots and live action tokusatsu heroes from different established franchises. The series makes this possible by using caricaturized versions of the characters (officially referred as "SD" or "Super Deformed" characters), which allowed the different heroes and villains to co-exist and interact with each other without the need to reconcile their contrasting styles and settings.
Dark Brain has begun his rampage across the SD world. Ultraman Taro, Kamen Rider v3, and the Knight Gundam have teamed up and tried to stop him. However, they were beaten. As a result, Ultraman Taro and Kamen Rider v3 were captured and Knight Gundam was killed. The original Gundam, Ultra Man and Kamen Rider 1 decide to take a stand and head on a journey to stop Dark Brain's forces once and for all.