Here is the full list of all 20 Slowdrive achievements.
Jump 40 meters
Get 3 stars on 15 levels
Faster than 3 stars for 1 second
Drive 10km
Drive on two wheels 15 meters
Achieve speed 50kmh
Jump 20 meters
Get 3 stars on any level
Get 3 stars on 30 levels
Get 3 stars on 60 levels
Find 15 leaves
Find 30 leaves
Find 60 leaves
Drive 100km
Finish the game
Complete all levels
Get 15 gold wheels
Get 30 gold wheels
Get all gold wheels
Get all ice wheels