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