I really like Final Fantasy XII but they should have just made it an ARPG. Just full-on party-based ARPG. I realize they would have to narrow spaces down to balance it out.
I feel if there is ever another Jet Set Radio. It should be an open world. This is a series that could really benefit from that. Not too large tho. If you take every area in the Future and merge them into one. That would be a perfect size.
I feel the same about Astral Chain II. Be a better open world. I don't typically like this way of thinking but the last 2 games I feel would work.
If we ever get another Castlevania. Return to the roots of the NES games and CVIV. Linear. Gothic. Horror-themed. No RPG elements. No anime. Dark, gothic, and atmospheric. 2D or 3D. Whatever. Just as long as it sticks to that.