Here is the full list of all 14 Raining Coins achievements.
Make a piggy bank huge.
Use 10 help lines in one day.
Use 10 piggy bank enlargements in one day.
Fail a level catastrophically.
Win a level with perfect score.
Finish the first world and unlock the next.
Finish the second world and unlock the next.
Finish the third world and unlock the next.
Finish the fourth world.
Finish world 1 with maximum score.
Finish world 2 with maximum score.
Finish world 3 with maximum score.
Finish world 4 with maximum score.
Finish 4 worlds with perfect score.