Boxer (20 points): In Episode II use correctly 5 combos fighting with looters.

Gunfighter (15 points): In Episode III kill 10 enemies using Concentration Mode.

Archer (20 points): In Episode IV kill 10 enemies using bow.

Driver (30 points): In Episode V kill 5 enemies when driving the coal cart.

Hatman (25 points): In Episode VI shoot 6 hats off from enemies' heads.

Slayer (20 points): In Episode VII defeat 6 enemies using the whip.

Accurate Guy (25 points): In Episode VIII kill McLyde brothers with 2 bullets only.

Untouchable (40 points): Finish Episode IX without taking a scratch.

Horseman (20 points): In Episode X kill 7 enemies while in the saddle.

Archeologist (25 points): Finish Episode XI in less than 10 minutes.

Spider Hunter (20 points): In Episode XII kill 10 spiders using the whip.

Fire Raiser (25 points): In Episode XIII kill 3 enemies using fire.

Eagles Eye (30 points): In Episode XIV kill 10 enemies by shooting them in the head with the sniper rifle.

Bow Expert (30 points): In Episode XV kill 10 enemies by shooting them in the head with the bow.

Earthquake (30 points): Playing as Miner kill 4 enemies with a single dynamite stick.

Lucy's Lullaby (20 points): Playing as Miner kill 3 enemies with a single shot from the sawn-off shotgun.

Quicker Than Hell (10 points): Playing as Gunslinger shoot 4 enemies using the quickshooters in less than 10 seconds.

Demolition (25 points): Playing as Gunslinger keep at 100% killing efficiency for X dynamite stick throws.

Headhunter (20 points): Playing as Sniper score 5 headshots in a row.

Blind Killer (10 points): Playing as Sniper kill 5 enemies with the sniper rifle without using the scope.

Surefire Hand (20 points): Playing as Rifleman shoot 5 enemies using the rifle without reloading.

Rifle Expert (20 points): Playing as Rifleman keep 100% rifle efficiency for 10 shots.

Additionally there are thirteen secret achievements, two of which remain unknown at this time.

Bounty Hunter (40 points): All Wanted posters found.

Story Mode Finished (60 points): Story Mode finished.

Very Hard Mode Finished (100 points): Story mode finished on Very hard difficulty level.

Long Distance (20 points): A distance of 10 miles covered.

Westman (20 minutes): Played for More than 24 hours (single player only).

Bonus Levels Finished (15 points): All bonus levels finished.

Duel Challenge Finished (20 points): Duel Challenge finished.

Young God (25 points): 6 bullets dodged in duel.

Fireworker (25 points): 10 dynamites shot in mid-air.

Killing Machine (50 points): 20 enemies killed in Multi-player mode without dying.

Legend of the Wild West (50 points): 300 enemies killed in Multi-player.

Very Hard mode:
After collecting 30 Wanted Posters.