Here is the full list of all 23 Loddlenaut achievements.
Leave GUP-14.
Reach the maximum loddle capacity in all biomes.
Run out of oxygen for the first time.
Encounter all loddle evolutions.
Have the maximum number of loddles following you.
Release a loddle into the open ocean.
Reach the maximum loddle capacity in a biome.
Pet a loddle.
Clean all biomes on GUP-14.
Find all Holo-Badges.
Find the abandoned CEO office.
Destroy 80 crates.
Enter Metzi Trench.
Unlock the Puddle Scrubber.
Cook a loddle snack.
Collect 500 pieces of litter.
Discover a loddle’s favorite food.
Evolve a baby loddle into an adult.
Find a Holo-Badge.
Clean up a goopy loddle.
Clean a biome to 100%.
Meet a loddle for the first time.
Complete the Home Cove tutorial.