Here is the full list of all 20 Asphalt 8: Airborne (Windows) achievements worth 200 gamerscore.
Have 10 cars
Beat Season 1
Win a race without using Nitro
Total 10 minutes of air time!
Have 50 Stars
Buy a new car
Buy your first car upgrade
Come in last place
Execute 25 Knockdowns
Drift 10 km
Perform 20 Perfect Nitro boosts
Get 1st place
Earn 10 medals during a race
Drift 1 m
Knock down the same car 5 times in a single race
Complete all seasons
Acquire 10,000 credits during a single race
Fully upgrade one stat of any car
Fully upgrade 1 car
Fully upgrade 3 cars