Full list of all 42 Cuphead achievements worth 1,500 gamerscore. It takes around 20-25 hours to unlock all of the achievements in the base game on Xbox One.
The base game contains 28 achievements worth 1,000 Gamerscore, and there are 2 DLC packs containing 14 achievements worth 500 Gamerscore.
Buy everything in Porkrind's Shop
Get every coin in the game
Complete all levels without killing an enemy
Obtain an A-Rank or higher on all bosses in Inkwell Isle III
Obtain an A-Rank or higher on all bosses in Inkwell Isle I
Get an S-Rank
Complete the game on Normal
Defeat the Devil
Obtain an A-Rank or higher on all bosses in Inkwell Hell
Give in to the Devil
Complete the Casino
Defeat every boss in Inkwell Isle III
Get every coin in all of the levels
Defeat a boss with an Extra Special move
Obtain all Super Arts
Parry five times before hitting the ground
Defeat every boss in Inkwell Isle II
Complete 100 parries
Defeat a boss with a Super Art
Defeat every boss in Inkwell Isle I
Find a shortcut
Complete 20 parries
Complete a level without getting hit
Defeat a boss
Obtain an A-Rank or higher on all bosses in Inkwell Isle II
Complete the game on Expert
Defeat King Dice without taking a hit
Defeat a boss using only the mini-plane bullets
Defeat the King's Gauntlet
Defeat a boss on Inkwell Isle IV without killing any of its minions
Defeat all of the King of Games' Champions
Obtain great power
Survive the nightmare
Complete your quest on Inkwell Isle IV
Defeat every boss in Inkwell Isle IV
Defeat a boss with one of Ms. Chalice's Super Arts
Defeat a boss with one of Porkrind's new weapons
Defeat a boss with Ms. Chalice
Obtain an A-Rank or Higher on all bosses in Inkwell Isle IV
Defeat 10 bosses with Ms. Chalice
Get an S-Rank on a stage of Inkwell Isle IV
Have 9HP at one time