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