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