Here is the full list of all 36 Jotun achievements.
The base game contains 33 achievements, and there is 1 DLC pack containing 3 achievements.
Defeat Odin without destroying any spears
Defeat Odin, the Allfather.
Defeat Kaunan, the terrifying Fire jotun.
Find all of Ithunn's Apples.
Find all of the God Shrines.
Defeat Isa, the mighty Winter jotun.
Defeat Fé, the magnificent Cave jotun.
Defeat Hagalaz, the mesmerizing Storm jotun.
Defeat Jera, the unmerciful Nature jotun.
Defeat Jera without taking any damage.
Defeat Fé without taking any damage.
Defeat Isa without taking any damage.
Defeat Hagalaz without taking any damage.
Defeat Kaunan without taking any damage.
Defeat Odin without taking any damage.
Defeat Jera in under 25 seconds.
Defeat Fé in under 25 seconds.
Defeat Isa in under 60 seconds.
Defeat Hagalaz in under 60 seconds.
Defeat Kaunan in under 80 seconds.
Defeat Odin in under 60 seconds.
Defeat Jera without using any God Powers.
Defeat Fé without using any God Powers.
Defeat Isa without using any God Powers.
Defeat Hagalaz without using any God Powers.
Defeat Kaunan without using any God Powers.
Defeat Odin without using any God Powers.
Defeat Jera without killing a single vine.
Defeat Fé without attacking her in melee.
Defeat Isa using only the icebergs.
Defeat Hagalaz without knocking her down.
Defeat Kaunan while at less than 10% health.
Beat the game 100%.
Beat Valhalla Mode.
Beat Valhalla Mode without taking any damage.
Beat Valhalla Mode without using God Powers.