Here is the full list of all 18 Simplz Zoo achievements.
Complete all 100 levels in the game
Purchase the Yeti
Purchase the Unicorn
Purchase the Saber-toothed Tiger
Increase your Zoo ranking to number 1
Raise your Zoo ranking into the Top 10
Raise your Zoo ranking into the Top 50
Raise your Zoo ranking into the Top 100
Create a match that gives you at least 250 of any resource
Purchase the Woolly Mammoth
Pass a level with under 10 seconds remaining
Pass a level with under 5 seconds remaining
Pass a level with under 2 seconds remaining
Purchase Mysterious Mansion
Match 8 tokens at once
Match 9 tokens at once
Match 6 tokens at once
Match 7 tokens at once