Here is the full list of all 11 Cat Search in Medieval Times achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
You found all the cats! Congrats!
Find all 120 cats without using hints
Found 100 cats
Found all the hidden wanted posters
Found 3 hidden wanted posters
Found 75 cats
Found 40 cats
Found 1 hidden wanted poster
Found 20 cats
Found 10 cats
Found 5 cats