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