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