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