I want the hotzone back, it was the darkest and most epic stage imo of DOA5 but I think that new stage that was shown in Christie's trailer will pretty much be Its successor. XD Geothermal power plant and the Naussau station wouldn't return since they're guest stages and savannah safari would be good again without that annoying random tiger.
The flow stage I would love back, I love when it gets stuck over the edge of the waterfall with that beautiful rainbow and then the music changes to be so dramatic and tense <3 I hope DOA6 has stages like that where the music climaxes in intensity and tone when certain actions are performed. The shrine stage I liked, and I would LOVE the opera stage back, especially on FIRE! <3 That's hands down the most beautiful and dark stage in DOA2U, I would love to whoop some ass in that place xD