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