Here is the full list of all 44 Shantae and the Pirate's Curse achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Saved Scuttle Town as fast as possible!
Defeated the Cyclops Plant without taking damage.
Defeat the Pirate Master's true form and save Scuttle Town in record time!
Complete the game without any Health upgrades and all Heart Squids collected.
Defeated the Steel Maggot without taking damage.
Defeated Dagron without taking damage.
Defeated the Squid Baron without taking damage.
Defeated the Empress Spider without taking damage.
Get Rottytops to Abner Tree without making any mistakes in a single attempt.
Defeated the Cyclops Plant using only Pike Balls.
Defeated the Ammo Baron without taking any damage.
Defeated the Pirate Master's true form without taking any damage.
Discover the secret Labyrinth.
Complete the hidden training room.
Defeat the Pirate Master's true form.
Collect all of the Dark Magic.
Defeated the Pirate Master without taking damage.
Defeated the Pirate Master.
Collect all Heart Squids.
Defeated the Steel Maggot.
Collect all Labyrinth maps.
Help Ammo Baron fire the Palace Disruptor Cannon.
Obtain the Spirit from Abner.
Collect the Enchanted Blade.
Play keep away with the Ammo Baron.
Sample the entire menu!
Defeated Dagron.
Destroy 20 bones with the Bubble Shield.
Obtain Manly Musk.
Defeat 50 enemies using Pirate Weapons.
Obtain the Fossil.
Collect 50% of the Dark Magic.
Defeated the Squid Baron.
Collect 50% of the Heart Squids.
Obtain the Golden Pickaxe.
Obtain all three Mummy Sketches.
Use a Pirate Flare to return to Risky's ship.
Defeated the Empress Spider.
Destroy 10 Spider Eggs before they hatch.
Obtain Squid Oil.
Defeated the Cyclops Plant.
Defeat 250 enemies using Shantae's Monster Whipper!
Release the Ham Stink.
Defeated the Ammo Baron.