SD Gundam G Generation Overworld

In the prequel “G Generation World” all the Gundam universes get thrown into a blender thanks to what is known as the Generations System, essentially a master computer that controls all of time and space, and thanks to it going haywire, all the Gundam universes are bleeding into each other.

Overworld picks up after World, where various different factions tried to destroy Earth (where the “World Signal” of the Generations System comes from) and failed. In fact, we find out why in this game, as the security system of the Generations System got corrupted and broke the system, causing time and space to go batshit.

In the meantime, all the Gundam Universes are essentially forced into a forever war in which events from their own canons bleed into other canons and they are effectively trapped in this cycle until the World Signal quits screwing up reality. Until then, death is uber cheap and everyone who dies just keeps getting brought back for another round of crazy crossover insanity.