Full list of all 70 We Happy Few achievements worth 1,540 gamerscore. It takes around 40-50 hours to unlock all of the achievements in the base game.
The base game contains 40 achievements worth 1,000 Gamerscore, and there are 3 DLC packs containing 30 achievements worth 540 Gamerscore.
Found all notes related to Prudence
Completed the entire game without directly murdering anyone
Finished Ollie's playthrough
Spread the Message
Found all collectibles
Injected yourself with glucose 10 times
Used 25 lightning rods, playing as Ollie
Completed "The Jack-o-Bean Club" encounter.
Completed "No Place Like Home" encounter
Completed Ollie's intro
Finished Sally's playthrough
Knocked out 50 NPCs with the Atomizer
Completed speaking with Verloc at the Joy Factory
Caught 40 butterflies with Sally's butterfly net
Completed the Crones encounter
Set foot on every island
Completed Sally intro
Finished Arthur's playthrough
Killed a guy named Ryan Andrews
Gained £1000 from looting/bartering across playthroughs
Talked to Johnny Bolton from the Secret Radio Room
Finished Mystery House without being spotted once
In Thomasina House - Collected all fake cats
Collected all Uncle Jack Shows
Died while overdosing on Joy
You successfully took Phlash as Arthur
Read all newspaper articles as Arthur, and redacted only the uncomfortable ones
Contracted and cured the plague
Listened to all the phone calls in the phoneboxes
Unlocked all of Arthur's shelters
Killed 100 NPCs across all playthroughs
Survived 50 days
Finished all of the butcher's apprentice quests
Delivered the cod liver oil
Retrieved the credentials from the club
Crossed into the Village for the first time
Completed "Band of Brothers" encounter
Completed Arthur's intro
Correctly sabotaged Clive Birtwhistle's redactor work
Took the Joy at the very beginning of the game
Destroy 50 Explosive Barrels
Get 100 Headshots
Pick Up All Lore Items
Kill 8 Robots in the Intro
Complete Act 1
Save all the Villagers
Complete Act 2
Complete Act 3
Push 7 Robots Into the Smelter
Complete the DLC
Lifetime Achievement Award
Survive Day 1
Survive Day 2
Vibe All Nick Statues
Blow Minds of 15 People After a Charged Facemelt
Serenade 30 people
Parry 30 attacks with the Vibe
Hit 3 NPCs with the Same Gold Record
Pole Dance Naked
Did Your Duty
Restored Order at Haworth Labs
Shut Off Joy Supply to Waterworks
Collected All Lore Notes
Unlocked All Upgrades
Found Loot in Alleyway
Found Loot in Canal
Knocked Down 40 NPCs With Whip Shove Combo
Zapped 20 Different TVs with Dart Gun
Finished DLC With No Upgrades