I considered the idea of an "open world fighting game" but I don't think it's necessary for DOA to go that far, and it would be limiting in terms of locations for character-building and storytelling, and would probably be terrible for gameplay/online reasons. But I wonder if it would even be possible to do, maybe in a new IP.
Free Step Dodge
inochinagi
Rob
Depends what you mean by biggest. Like DOA5 aircraft carrier big or sprawling multi-tiered stages? I thought DOA2's stages were too big and 2U making them more compact improved the gameplay. 3 and 2U are my favorites for stages, I think they got the balance just right on those.
deathofaninja
I don't think it will ever get bigger than the museum.