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