Level: Easiest

Level: Easy

Level: Normal

Level: Hard

Level: Hardest

Level: Single Mission 1

Level: Single Mission 2

Level: Single Mission 3

Level: Single Mission 4

Level: Single Mission 5

Level: Single Mission 6

Level: Single Mission 7

Level: Single Mission 8

Level: Single Mission 9

Level: Single Mission 10

Level: Single Mission 12

Level: F.N.G.

Level: Crew Expendable