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