Darkwatch
Here is the Requirements for the Gunslinger mode in Extras, complete these tasks to unlock art for that specified level.
Unlockable: How to UnlockAllies art, Bosses Art: Complete Curse Of The West on Shootist Difficulty
Attract Mode Movie: Complete Dead Light Prism with 80 or more Kills
Cowboy Animatic: Complete Torture Maze with 30 or more Melee Kills
Darkwatch Archives: Complete all Gunslinger levels on Deadeye
Enemies 1: Complete Boneyard with 65% or more Accuracy
Enemies 2: Complee Showdown with 20 or more Melee Kills
Environments 1: Complete Darkwatch Outpost with No Deaths
Environments 2: Complete Invasion on Deadeye Difficulty
Environments 3: Complete Curse Of The West in 10 Minutes or less
Evolution of Jericho: Complete the Single Player Campaign on any difficulty
Highmoon Trailer: Complete Rescue in 15 Minutes or less
Rescue Intro Movie: Complete Hangtown with 20 or more Headshots
Showdown Animatic: Complete The Right Train on Shootist Difficulty
Vehicles: Complete Deadfall with 20 or more Headshots
Weapons: Complete Morning After with 70% or more Accuracy
Wrong Train Animatic: Complete The Wrong Train with 65% or more Accuracy
Submitted By: Barfy