Here is the full list of all 39 Little Kitty, Big City achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Use an emote
Get your very own camera
Get kicked out of a store
Leave your pawprints in the wet concrete
Knock a human over by jumping on them
Capture a bird in flight
Get a human to kick a ball to you
Smash 10 items
Find your way back home
Meet all the animals
Collect all the ducklings
Get your first yummy fish
Eat all the yummy fish
Find 200 Shinies
Collect all the hats
Open all Tanuki's portals
Sleep in all the cozy nap spots
Catch (and release!) 20 birds
Enjoy 5 cardboard boxes
Recycle 100 items
Break 100 objects
Bust all the old birds' nests
Bring bones to all the dogs
Get petted 10 times
Get photographed 20 times
Take 20 photos with your camera
Investigate 10 trash cans
Complete all items on your To-Do list
Score every soccer goal
Make a human slip on a banana
Make 20 humans stumble
Remove all the chess pieces from the board
Splash paint on the fancy car
Put 4 rubber ducks in the pond
Chase a human with a dangerous item
Use your noggin on the soda machine
This must be how Gecku feels all the time! Raaaaaaaah!
Meow 10 times in a row
Drop a phone into the portapotty