Here is the full list of all 52 Gangs of Sherwood achievements.
Perform a Finisher
Defeat The Ram
Be in Rebel Instinct for a combined total of 2 minutes
Earn an S-rank in any encounter
Activate Rebel Instinct
Eliminate Guy of Gisborne
Revive an ally
Perform a 100 hit combo
Launch 50 different enemies
Grapple Attack 25 enemies
Finish any Mission with more than one player
Donate 5000 Gold at the end of any Mission
Raise the Gang's Power to Level 4 while in any Mission
As Robin, successfully fire a total of 100 Star Arrows
Find and equip your first Artifact
Get a Headshot Kill on an enemy
Purchase an Outfit at the Remington Cole
Perform an Air Combo
Complete Major Oak Calls
Donate Gold to a Resistance's Checkpoint
Complete all the story acts on Normal difficulty
Complete all the story acts with all heroes
Finish every mission with more than one player
Kill all of Marian's siblings
Eliminate the Prioress of Kirklees and Red Roger
Eliminate the Sheriff of Nottingham
Kill 15 enemies by pushing or throwing them off ledges
Perform 15 Parry Attacks in total
As Friar Tuck, successfully perform 100 Charge Attacks
As Little John, successfully perform 100 Heat Attacks
Perform 25 Finishers
Complete the Tyrant's Pit in under 10 minutes
Perform a Rebel Ability
Perform a Throw on a enemy
Defeat an enemy by lighting them on fire
Push an enemy so they fall off a ledge
Purchase the Origin Outfit at Remington Cole
Complete all the People's Requests
Unlock all Gears for all for one hero
Unlock all Gears for all for all heroes
Complete all Challenges
Complete all Lessons
Buy everything from Antonna Carridge with all Heroes
Buy everything from Antonna Carridge with one Hero
Find and equip all the different Artifacts
Find all the Gang's Mementos
Find all of Alan-a-Dale's puppets
Kill all the Crows in Edwinstowe
As Robin, get killed by the Prioress of Kirklees
High five with an ally
Kill an enemy by throwing Gold at them
As Marian, successfully perform 100 Flux triggers