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