Here is the full list of all 22 Ever Seen A Cat? achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Find all the individual cats in the abstract place.
Got all the achievements!
Find 1000 cats from any place.
Find all the individual cats in candyland.
Find all the individual cats in the park.
Find all the individual cats in the field.
Find all the individual cats in the galaxy.
Find 500 cats from any place.
Find all the individual cats in the town.
Find all the individual cats in the forest.
Cleared all places one time.
Cleared candyland for the first time.
Cleared the park for the first time.
Cleared the field for the first time.
Find all the individual cats in the home.
Cleared the home for the first time.
Cleared the galaxy for the first time.
Cleared the town for the first time.
Find 100 cats from any place.
Cleared the forest for the first time.
Find all the individual cats in the garden.
Cleared the garden for the first time.