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