Here is the full list of all 20 Antigraviator achievements.
You lapped someone
Play all the maps in the game
Compete in 400 death races
Break the soundbarrier
Win an online race
Unlock the crocco
Keep a constant speed
Unlock the X1Z1
Win a race with second place finishing within 0.5 seconds of you
Finish your first League
Avoid taking damage during a race
Buy your first item
Finish your first race
Do not die during a race
Finish the Legends League
Buy all items
Set 500 traps that get triggered
Play 400 quick races
Play 400 countdown races
Make the bridge jump in Serpentine Valley