Here is the full list of all 12 Wheely achievements.
Complete the first level
Get 10 stars
Get all stars in new wheel story
Get all stars in time travel story
Get all stars in armageddon story
Get all stars in fairytale story
Get all stars in detective story
Get all stars in aliens story
Get all stars in race story
Get all stars in love story
Get all 252 stars
Get 126 stars