Muv-Luv：Chronicles

You are swept from a peaceful world—one where the BETA never existed—by a flash of blue-white light into an alternate Earth, a timeline rewritten as far back as 1973. Here, Tactical Surface Fighters clash with colossal metallic beasts amidst the ruins; stepping into the shoes of (or becoming) Takeru Shirogane, you must join forces with comrades-in-arms at Yokohama Base and confront a war that will determine the very survival of humanity.