Fortified

Fortified is a strategy shooter in which players defend the Earth against a menacing Martian invasion in the 1950s. Play as one-of-four pulp inspired heroes as they fight swarms of terrifying robots with an arsenal of Cold War era weapons and experimental technology. Protect the city by building a network of defensive structures, commanding an army, and jumping into battle against dangerous sky scraping attackers. Fight for Earth alone or with up to four players for the ultimate co-op defense experience. [Xbox.com]