Here is the full list of all 21 Cornucopia Demo achievements.
Catch your first Large Fish
Harvest your first Berry Bush
Harvest your first Vegetable
Decorate your Home for the First Time
Refine 10 Times
Brush an Animal
Plant your first Seed
Feed Munger for the First Time
Open your first Letter
Give your first Gift
Steam Train was Spotted
Defeat the Spider Boss
Earn 10,000 Gold
Harvest your first Fruit Tree
Try Every Scratch Card
Catch 10 Fish
Discover the Old Mines
Get Stuck in the Waterwheel
Catch your first Fish
Bomb an NPC
Pass out from Exhaustion