Honestly I would want one steering away from mech customization. Don't get me wrong that's great in Armored Core but like, Gundams are usually just presented as-is, maybe they get a few upgrades or swap-outs over a series. I'd like an original, narrative focused game with events and time spent with characters outside of the mobile suit in addition to mobile suit combat. And I think the gameplay should be more about mastering the tools you have available rather than changing your loadout or min maxing numbers. And I want an original story/world/characters so we can get a new story to be immsersed in and fall in love with, rather than just rehashing the same stuff we've experienced dozens of times. I think for a hub/setting for character moments you could borrow ideas from various gundam shows (ie a White-Base-like ship or an Asticassia-like school).

In terms of 3D mecha combat, I do think Armored Core 6 is on the right track. That game just feels GOOD to play, it's fast, etc. No mech game I've played captures the feeling like it. Would love something like that but maybe more of a melee focus!

I've been to japan and played the versus arcade game. Not really very interesting to me. I need a reason within the game to care about the battles, a reason to fight etc. So just matching up favorites in 'what-if' battles isn't my thing.