Here is the full list of all 15 High On Racing achievements.
You finished Level 5
You finished Level 4
You finished Level 3
You finished Level 2
You finished Level 1
You finished Level 6
You finished Level 7
You finished Level 8
You finished Level 9
You finished Level 10
You finished Level 11
You finished Level 12
You finished Level 13
You finished Level 14
You finished Level 15