Here is the full list of all 13 Cozy Island Idle achievements.
Catch your fist fish
Get your first Diamond
Reach Profit Tier II
Get 1k Coins
Get 10k Coins
Get 100k Coins
Get 500k Coins
Get 1M Coins
Reach Profit Tier III
Reach Profit Tier IV
Reach Profit Tier V
Buy the Jetski
Get 60 fishes