The Guardian Trials Add-on for Super Lucky's Tale has 13 achievements worth 395 gamerscore.
Complete all Skill Levels
Complete all Combat Levels
Complete all Marble Levels in the Foxington Hub
Defeat all of the Levels in Foxington
Interact with all 5 radios in the Foxington HUB
Never get caught in a single run through of Under Pressure
Defeat all of the enemies in Top That!
Take a shower in Foxington HUB
Take no damage in the WriggleMania
Find all 4 diamonds in A Road to Nowhere
Die in the Foxington Hub
Collect all of the collectibles during the cross ladder section of Step by Step
Defeat WriggleMania while wearing the Maxi-Mullet