I was just thinking that Xenonauts is so close to perfect. There's a few design decisions that need reworking, like progression could be smoother like you said, rotating views for easier observation, custom color palettes, easier to compare stats in the in-game guide so that the wiki isn't needed on first playthrough, maybe some more in-depth air combat. But then you get to the bugs like how sometimes clicks don't register, or how alt-tabbing messes everything up, or how there's no linux/mac version due to engine constraints, and it got me thinking "too bad they can't just remake the game now that they know what they do now." And here you are suggesting just that! I think it's a great idea and I'd buy it.
I think instead of removing the "all in this together" aspect a better idea would be to have 2 types of bases: the regular ones and smaller, more numerous bases. That's how real life is, right? Like they'd just have radar and airstrips, and the aliens would only attack the large bases with troops (for simplicity's sake and hey, they're more appealing targets anyway). Maybe even adding in aircraft carriers to extend range could be a fun idea! Still, human on human combat could be fun. (Exalt anyone?) Perhaps you could have it that the world at large was united by the threat of invasion, but there are still ideological terrorists attempting to take you down in an attempt to re-ignite the cold war. So occasionally you'd fight rebel communists, or a capitalist mercenary firm. They'd be more concerned with their ideals than the threat of extinction.
Another thing to consider is that Xenonauts is great at building tension in a way that Firax-Com doesn't. I'm afraid to go around corners or stand too close to buildings because I never know what's gonna happen. But Xenonauts never really uses that tension, the reaper will go in a guy's blind spot and then he'll disappear. 3D will probably help this, but make sure you keep the tension level high!
