Here is the full list of all 44 Nuclear Throne achievements. It takes around 200 hours to unlock all of the achievements on Windows.
Get 100% of the unlocks.
Unlock a Golden Disc Gun or Golden Nuke Launcher.
Unlock all Crowns as one character.
Reach Level Ultra as Skeleton.
Sit on the Nuclear Throne as headless Chicken.
Defeat Captain.
Defeat Captain as Rogue.
Play as Frog.
Defeat the Technomancer as Steroids.
Loop as every character.
Unlock a Golden Weapon for every character.
Reach 2-1 on Hard Mode as Chicken.
Defeat Hyper Crystal as Horror.
Defeat Mom as Rebel.
Eat a Hyper Weapon as Robot.
Reach the Nuclear Throne with Melting without choosing Rhino Skin or Strong Spirit.
Reach the Nuclear Throne in under 10 minutes as Plant.
Reach 4-? as Crystal.
Reach 5-?.
Reach 3-?.
Reach 2-? as Eyes.
Defeat Horror.
Unlock Hard Mode.
Defeat the Technomancer.
Unlock a Golden Weapon as any character.
Defeat Hyper Crystal.
Defeat Mom.
Loop past the Nuclear Throne.
Defeat Throne II.
Loop the game.
Reach 7-3 on a Daily.
Reach Level Ultra as any character.
Unlock a Crown as any character.
Reach the Nuclear Throne.
Defeat the Nuclear Throne.
Reach 6-1.
Defeat Lil Hunter.
Reach 5-1.
Defeat Big Dog.
Reach 3-1.
Reach 2-1.
We hereby sincerely apologize.
Die.
Defeat Big Bandit.