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