Hint: During the single player campaign, you take the role of a Marine called Bitterman, taking part in "Operation Alien Overlord", attempting to save Earth from the Strogg invasion by counter-attacking their planet, Stroggos. During the first attack on Stroggos, the Big Gun strikes down most of the Marine pods with a powerful EMP blast. This causes most of the pods to crash land (many miles from their target landing zones). Most of the Marines are captured or killed, but Bitterman is one of the lucky few to survive.