Here is the full list of all 41 Helheim Hassle achievements.
Finish Prologue.
Become the God of Puzzles.
Find every soul coin.
Be a bad Bjørn.
Assemble The Belt Of Secrets.
Help out Fenris.
Survive the fight with Pesto without taking damage.
Buy everything in Stonemart.
Drink every smoothie.
Find Idunn.
Find the souvenir in Einar's Crazy Puzzle Extravaganza.
Win every race with Erica.
Learn every song.
Find all the gold.
Who's a good Bjørn?
Solve every puzzle.
Find every letter.
Fully decorate your house.
Gain access to the Laughter Gland.
Try out every limb combination.
Listen to everything Modgunn has to say.
Give feedback.
Give the fountain enough money.
Finish the main story.
Let poor Andre know you're okay.
Finish Helheim City.
Finish Winterberg County.
Finish Entrance County.
Send Mike Cobbles to Hell (in a nice way).
Help every stone person.
Be disappointed.
Single-handedly save the indie-puzzle scene.
Find a soul coin.
Have three heads on you at once.
Finish Riverrum County.
Pick every berry after the prologue level.
Throw and catch Bjørn's head 5 times without dropping it.
Pet every animal.
Change your appearence in every slot.
Climb to the top of Polyester Peak.
Have a gamer moment and get every achievement for Helheim Hassle.