Full list of all 101 Skul: The Hero Slayer achievements.
The base game contains 57 achievements, and there are 5 DLC packs containing 44 achievements.
Restore the Demon King Castle to its original form
Defeat the First Hero without getting hit
Keep talking to Headless
Defeat the First Hero as Little Bone
Defeat the First Hero without saving the stage NPC
Play on Rookie Mode
Acquire Vanguard Captain
Acquire Joker
Acquire Gold Gargoyle
Acquire Magnifico
Acquire Nightmare
Acquire Sniper
Acquire Eternal Mummy
Acquire Warlord
Acquire Abyssal Monarch
Acquire Soul Knight
Acquire Destroyer
Acquire Super Rock Star
Stay in the black market for 5 minutes
Defeat Chimaera without getting hit
Defeat St. Joan II without getting hit
Acquire Eternal Werewolf
Acquire Neo Samurai
Acquire Demolitions Expert
Acquire Royal Guard Captain
Acquire Poseidon
Reach the top of the chandelier in the Demon King Castle
Acquire Frozen Spirit
Acquire Dark Avenger
Acquire Desperado
Acquire Carleon Commander
Acquire Minotaurus III
Acquire Defender Captain
Kill 100 adventurers
Acquire Devil Berserker
Acquire Ghoooooul
Acquire Elder Ent Skull
Defeat the Leiana Sisters without getting hit
Acquire Arch Lich
Acquire Gambler
Keep restocking from the collector
Reach the top of the throne in the Demon King Castle
Rescue the Demon King and return to the Demon King Castle
Defeat the Sword of Carleon, the First Hero
Defeat the archbishop of the Leonia Order, St. Joan II
Acquire Dark Alchemist
Acquire Grim Reaper
Defeat the distorted goddess, Chimaera
Acquire Master Ninja
Acquire Yaksha
Defeat Yggdrasil without getting hit
Defeat the adjutants of the Gold Mane Knights, the Leiana Sisters
Acquire Champion
Die from a trap
Defeat the elder ent, Yggdrasil
Return after experiencing death
Stay in the black market for 1 minute