Here is the full list of all 59 Brutal Legend achievements. It takes around 35-40 hours to unlock all of the achievements on Windows.
Ride one of every ridable animal.
Complete all hunting secondary missions
Purchase all upgrades in the Motor Forge
Unlock all songs in the Mouth of Metal
View all Legends
Free all 120 Bound Serpents
Complete 20 ambush, outpost defense, or mortar secondary missions
Kill 15 enemies with a Metal Beast while wearing the Zaulia Threads.
Acquire 3,000 Fire Tributes
View all vistas
Make out with Ophelia while wearing the Mountain Man Threads.
Visit the grave of a fallen hero while wearing the Black Metal Threads.
Complete Campaign mode on Gentle
Complete Campaign mode on Normal
Complete "Sea of Black Tears"
Summon all Motor Forges
Free 80 Bound Serpents
Complete all racing secondary missions
Learn all guitar solos
Kill 20 Tainted Coil units with the Disgorger.
Run down 20 animals in the Deuce with the Coiling Maw equipped.
Personally smote 300 enemies - any mode
Double Team with every Ironheade unit
Complete "Dry Ice, Wet Graves"
Kill 20 Drowning Doom units with the Eye of Sorrow.
Slay 150 enemies with the Deuce - any mode
Jump over a Hextadon in the Deuce
Free 40 Bound Serpents
Complete "It's Raining Death"
Complete "Sanctuary of Sin"
Complete "Pilgrimage of Screams"
Complete "Battle for Bladehenge"
Gain 5 or more seconds of hang time in a single jump - any mode
Complete "Lair of the Metal Queen"
Chisel four Razputin heads onto Mt. Rockmore.
Complete "Exploited in the Bowels of Hell"
Purchase 1 upgrade in the Motor Forge
Complete "Welcome to the Age of Metal"
Achieve 100% completion on the stats screen
Win an AI stage battle - any difficulty
Win a ranked multiplayer match
Win 10 match-made multiplayer battles.
Win 50 match-made multiplayer battles.
Double Team with every Drowning Doom unit
Double Team with every Tainted Coil unit
Win a single-player Stage Battle against the AI using only orders
Spend 250,000 fans - any mode
Play with or against another player who has this Achievement
Trap 15 enemies in one ring of fire with the Fire Baron's Double Team
Kill 25 enemies with the grinder of one Rock Crusher
Hit 6 enemies with the explosion from a Brood's Double Team
Hit 15 enemies with one Agony Ball using the Pain Lifter's Double Team
Kill 20 enemies with one Bleeding Death
Ride a Razorfire Boar into the Sea of Black Tears and live to tell the tale.
Kill a Tollusk using only Ground Urchins
Complete Campaign mode on Brütal
Win an AI stage battle - Brütal difficulty
Play a multiplayer game on all Hammer of Infinite Fate multiplayer maps.
Win 10 games on Hammer of Infinite Fate maps - ranked or vs. the Brütal AI.