Natural Selection 2 (2012)

murder survival horror snake villain damsel in distress bloody death steam time limit over the shoulder one-man army boss fight explosion voice acting human polygonal 3d profanity sniping melee a.i. companion difficulty level game with chapters plot twist ambient music kidnapping pax east 2012 tragic hero breaking through windows male protagonist action-adventure swimming retail games with steam activation instant kill minigames non-player character black market steam trading cards dog pax prime 2013 pax east 2013 traps shopping mercenary undead upgradeable weapons disease female protagonist backtracking femme fatale leveling up aliens mutants extreme violence gore system countdown timer interactive environments item combination mod support animal cruelty context sensitive alternate costumes merchants super strength invisible enemy surprising character switches save point checkpoints respawning unlockables auto-aim giants resource gathering chicken iron maiden infinite ammo quick time event button mashing shooting range evil organization no jumping duel motion capture animation pax east 2014 pax prime 2012 high score compilation unlockable difficulty level speedrun kill streak playable boss bots character select screen valve anti-cheat dedicated servers crowd control clan multi-phase boss close quarters combat death match sea monster mod origin transforming boss steam workshop running towards the screen alien protagonist