Here is the full list of all 26 A Walk With My Dog achievements.
You finished the walk
Picked some tasty mushrooms
Took the plastic trash back home
You "fought" the snowman
You let the dog enjoy the squeaky toy
It looks like my dog
Keeps the doctor away
You lost the dog but then you found it again
Why did you touch it?
You found some photos
Find all photos
Find the buried treasure
Walk 10,000 steps
You put the pieces back together
Can I call him Pepe?
Hit all the lillypads
You heard the bell at the church
Have you ever questioned the nature of your reality?
Play tug for at least 20 seconds
You caught three types of animals
You scared a big bird flock 4 times
Made the dog quite happy
Collect three special balls
You got a good score on the game console
You took him back home to the garden
You solved all the puzzles