Alien Syndrome Single Player Annihilate more than 100 vicious alien species in high-speed combat Discover hundreds of weapons, armor types, and special abilities in this Shooter-RPG Tackle the intense four-person co-op multiplayer mode In-depth gameplay with 15 intricate levels and multiple side quests &#8211; 20+ hours of action-packed adventure. Single Player Annihilate more than 100 vicious alien species in high-speed combat Discover hundreds of weapons, armor types, and special abilities in this Shooter-RPG Tackle the intense four-person co-op multiplayer mode In-depth gameplay with 15 intricate levels and multiple side quests &#8211; 20+ hours of action-packed adventure.