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