Here is the full list of all 21 Little Dog achievements.
To be at level 5 for more than three minutes
Jump 100 times
Die 30 times from cliffs
Die 30 times from bat
Die 25 times from plants
Click on "Exit"
Click on "Play"
Click on "Menu"
Reach level 12
Reach level 11
Reach level 10
Reach level 9
Reach level 8
Collect 40 bones
Reach level 7
Reach level 6
Reach level 5
Reach level 4
Reach level 3
Reach level 2
First level started