Hrm, I have a theory for the bad performance of DQ8.
I think what they did was lock the entire engine to the framerate of the character animations.
My reasons for this theory:
- The iOS version is pushing less geometry than the PS2 version, and there are other iOS games out there that can maintain 60FPS no problem with more detailed assets.
- The shitty performance is consistent, whether it's outdoors or in a town or inside a building. If it were simply an optimization issue, I would expect to see at the very least a higher framerate indoors.
- The performance issues affect the UI buttons. and the game stops updating the game screen while in the menu so there's no excuse for rendering overhead to be impacting the UI.
- If you focus on your characters movements, the performance actually seems okay. It's not until you start panning or tilting the camera that you really notice it. Similar to how in films, the limits of the 24fps framerate become a lot more evident when panning the camera.
Conclusion: performance issue probably has more to due with developer unfamiliarity with Unity (or possibly inherent Unity limitations) than with poor optimization.
I've submitted a ticket, but I don't have high hopes.
Unfortunately this also means that a more powerful device is unable to measurably impact the performance, beyond reducing the occasional dropped frame.