The Muv-Luv series is an epic saga told in three parts: Muv-Luv Extra, Muv-Luv Unlimited, and Muv-Luv Alternative. What begins as a tongue-in-cheek romantic comedy ultimately transforms into an action-packed thrill ride in a war-torn alternate reality, and it’s this drastic-yet-methodical genre twist that makes the final chapter the most highly-revered visual novel of all time.

This game contains the first two arcs: Extra, and Unlimited. 
The final arc, Muv-Luv Alternative is the story’s massive climax, and is nearly the size of the first two combined