Here is the full list of all 30 Bugsnax achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Complete the adventure at Broken Tooth.
Complete the main story of Bugsnax.
All of the Grumpuses survive.
Complete all of the side quests.
Catch 100 unique species of Bugsnax.
Defeat all of the Legendary Bugsnax.
Collect 10 hats.
Return every Grumpus to Snaxburg.
Fully transform every Grumpus.
Watch all of Lizbert's video diaries.
Interview every Grumpus.
Scan a Grumpus after saucing them with cheese.
Solve the secret of the lava cave or the secret of the dunes.
Fully furnish your hut.
Transform a Grumpus with Scoopy, Banopper, and Cheery.
Stun a Bugsnak with the Trip Shot attached to your Buggy Ball.
Empty one biome of all its Snakpods.
Donate max amount of Bugsnax to Gramble's ranch.
Catch 50 unique species of Bugsnax.
Transform Gramble.
Transform a Grumpus with Bunger, Fryder, and Sodie.
Steal Beffica's diary from her cave.
Stun a flying Bugsnak by launching another Bugsnak at it.
Catch 25 unique species of Bugsnax.
Fully transform a Grumpus.
Catch more than one Bugsnak in your Snak Trap at once.
Scan the Snaxsquatch.
Find your way to Snaxburg.
Catch your first Bugsnak.
Check behind the waterfall for secrets.