ARMA: Armed Assault

Armed Assault is a military FPS from Bohemia Interactive and IDEA Games. Gameplay and technology is similar to Operation Flashpoint, which was also developed by Bohemia Interactive. The campaign takes place on a fictional Atlantic island, and follows a conflict between a communist regine and a democratic monarchy. You play as a US soldier in a squad, and must aid the local militia in fending off an offensive by the northern regime. Gameplay, like Operation Flashpoint, emphasizes realism, attention to detail, and very large maps (up to 250 square miles).