The plot of the game centers around a megalomaniac named Kreel who has become a global threat and is threatening various nations with his seemingly unstoppable armies. Players take the role of two pilots named 'Hatch' and 'Walker', who are part of an international force devoted to fighting Kreel and his varied minions. As the campaign progresses, the source of Kreel's power is revealed to be Red Mercury, which provides his forces with their nigh-invulnerability. The game has various endings depending on what actions the player takes.