Here is the full list of all 31 Hidden Office achievements.
Snowshoe 2
All levels completed
Persian 2
Striped Tabby 2
Tabby 3
Maine Coon 3
Siamese 3
Somali 3
Russian Blue 3
Maine Coon 1
Sphynx 2
Maine Coon 2
Siamese 2
Persian 3
Snowshoe 3
Janese Bobtail 2
Siamese 1
Janese Bobtail 3
Russian Blue 2
Janese Bobtail 1
Somali 1
Tabby 2
Sphynx 1
Snowshoe 1
Russian Blue 1
Striped Tabby 1
Sphynx 3
Striped Tabby 3
Somali 2
Tabby 1
Persian 1