Here is the full list of all 9 Rent's Due: The Game achievements.
You found a very well known sword stuck in a campfire
You beat 5 levels on Normal Mode.
You beat 10 levels on Normal Mode
Found a curious Hockey mask & Machete
You beat 15 Levels on Normal Mode
You beat 20 Levels on Normal Mode
You found Freddy the Bear
Found a very famous quote
Found a Kitchen Knife stuck in a Pumpkin