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