Muv-Luv Alternative: Total Eclipse 

"There is hope that can only be born in the depths of despair, and a future that only hope can create..." In 1973, following the ruthless six-year-long Lunar War, the hostile alien species known as the BETA—Beings of Extra Terrestrial origin which are Adversary of the human race—invaded Earth, killing billions and decimating Eurasia. With the nations of Eurasia having fallen to the BETA, their survivors race to develop a new tactical surface fighter at a base in Alaska. Yuuya, an ace pilot with a bad attitude, is reassigned from the U.S. Army to the joint US/Japan TSF development project. There, he meets pilots from Nepal, Sweden, Egypt and all over the world... including a by-the-book imperial soldier named Yui. The two instantly become constantly bickering enemies, and soon he meets the mysterious duo of Soviet pilots known as the Scarlet Twins, Cryska and Inia.