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