I know it's a bit too "Visual Novel" for an action-geared game but it'd have been cool to have Mei's plot more actively ongoing alongside the main story, maybe have her meet the various super scientists from the other IPs and have them weigh in on Archetype and everything going on with the kaiju.

Fuck, maybe give us a guest-only stage where Wufei, Sai, Athrun and some other NPCs show up to fight off Salunga.