Bomberland

Bomberland is the setting of the game Wario Blast: Featuring Bomberman!

Bomberman series
The setting of the NES Bomber Man game was an unnamed underground compound, which was the reluctant home of the original bomb-producing Bomber Man robot until he was encouraged by a rumor that robots escaping to the planet's surface become human. The aforementioned planet subsequently appeared to be Earth, but was eventually named and revised as Bomber Star (aka Planet Bomber), one of many locations in the Bomber Nebula.

Wario Blast: Featuring Bomberman!
Wario somehow has found the extra-dimensional portal that links his world to Bomberland. Thinking of claiming the riches and people of this world as his own, the greedy character entered the portal, but was met with more resistance by the Madbombers than he'd anticipated.