Here is the full list of all 27 Ooblets achievements.
Sell 100 crafted items
Scan 25 ooblets at the Lernery
Sell 50 crafted items
Travel to Pantsabear Hill
Travel to Tippy Top
Collect forageables from 4 different regions
Travel to Port Forward
Win 3 dance barn tournaments
Collect 40 things from the sea dangler
Complete 20 Tinstle Tasks
Craft 20 items
Fulfill 15 Plenny's orders
Travel to Nullwhere
Win 15 dance battles
Scan 10 ooblets at the Lernery
Complete 10 Tinstle Tasks
Get 10 friendship stickers
Travel to Mamoonia
Get 3 friendship stickers
Scan 3 ooblets at the Lernery
Harvest 50 crops
Win 5 dance battles
Complete 5 Tinstle Tasks
Get 150 friendship points
Plant 15 seeds
Look at 10 thingiedoodles
Collect 60 forageables