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Kill 200 Strong Martian

Complete 1 mission without picking up any Ultra Charges

Reload your extra weapon 1,000 times

Complete all Mars missions

Complete a multiplayer mission without damaging any allies

Eliminate 200 zombies with melee attacks

Eliminate 1,000 Zombie Evaders

Eliminate 100 Martian Teleporters
Minimum OS *: Windows® 7/Vista/XP Processor: Intel core 2 duo 2.4GHz Memory: 1GB for XP/2GB for Vista/7 Hard Disk Space: At least 2.5GB of free space Video Card: DirectX 9 compatible video card with Shader model 3.0. NVidia 7600, ATI X1600 or better DirectX®: 9.0c Sound: DirectX 9.0c compatible sound card