Ristin's Campaign Construction Center
Long story short, the RIFTS Macross game system looks solid and with some heavy-handed bludgeoning the setting could be made workable too. Unfortunately, my love of the Macross mecha stems from nostalgia; and since that’s not commonly shared I don’t think I could get a PC group sufficiently invested to give it a chance.
Macross has a “expanded setting” that goes beyond the three Robotech stories, and that’s where one would want to set the story. Either a colony fleet (Like Macross Frontier or Macross Galaxy in Macross Frontier) or a non-Earth colony (like Eden colony in Macross Plus).
Taking the lesson from Macross Frontier, the PCs should be with a mercenary unit or small military contractor (or pirates, etc) to give the PCs proper independence. And also the NPCs they’d be living and working with would be more personal to the PCs than a vast heirarchy of military superiors and subordinates.
But the fact remains that such a game would have to be a labor of love between people that love the setting and want to give it a run…which isn’t going to happen any time soon.