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