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