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