I always liked the flip button, the only thing I would worry about is copyright issues with Sony. That's the only way that a main cannon would work though, although that might interrupt the speed flow of the game. I guess the minigun could just be a locking cannon, so it would be less powerful. Also, just because it's "locking" doesn't necessarily mean that every shot hits. It could be programmed to where it can't turn very fast so the Zombie ships can avoid some of the bullets to make it more fair.

My concept really does look like the FEISAR Prototype, doesn't it? I never really noticed that, but once you said it, I see exactly what you said, it does have a lot of resemblance. I've always been a fan of the 2048 style ships, so I guess that's shining through.

I like your ideas for Sao Paulo, that's what I would guess that they are planning to do, maybe with some skillcuts, narrow sections, and stuff like the 2048 tracks. Overall I think we have a good start on this mode, with some work to do, but we'll get there!