Here is the full list of all 31 Ultros achievements.
Defeat Vasa, the Huntress.
Defeat the Gluttonous Feastro.
Defeat the Enraged Moth Beast.
Kill an enemy with another enemy.
Connect at least one of each plant species to the living network.
Gather one specimen of every fruit, ten in total, in one juicy pile.
Gather one specimen of every critter's non-battered guts, twelve in total, in one juicy pile.
Watch all Vistas.
Take the violent path towards awakening Ultros.
Defeat Higher Suggajof Brunzon.
Lead plants into the great refinery hall for Brunzon to discover.
Connect the Shaman in Gärdner's Garden.
Connect the Shaman in Geggamoja Refinery.
Connect the Shaman in Infinity Lake.
Connect the Shaman in Pantheon of the Stars.
Connect the Shaman in Temple of Motherhood.
Connect the Shaman in Rotten Orchard.
Connect the Shaman in Vasa's Legacy.
Feed the Enraged Moth Beast.
Feed the Gluttonous Feastro
Unlock all cortex skills.
Grow a plant that combines elements from all different plant species.
Fully upgrade the Extractor
Take the non-violent path towards awakening Ultros.
Defeat the parasitical Host.
Give the Host new input to analyze.
Defeat the three Dorok sisters.
Connect the three Dorok sisters.
Uncover every part of every area on the map.
Escape Entrance without sword.
Bring the sword statue to a standstill.