Here is the full list of all 20 Antigraviator achievements.
Win an online race
You lapped someone
Keep a constant speed
Play all the maps in the game
Avoid taking damage during a race
Make the bridge jump in Serpentine Valley
Unlock the crocco
Break the soundbarrier
Unlock the X1Z1
Finish your first League
Buy your first item
Win a race with second place finishing within 0.5 seconds of you
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
Compete in 400 death races
Play 400 countdown races