Here is the full list of all 20 Antigraviator achievements.
Unlock the X1Z1
Break the soundbarrier
Buy your first item
Finish your first League
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
Win an online race
Set 500 traps that get triggered
You lapped someone
Keep a constant speed
Play 400 quick races
Compete in 400 death races
Play 400 countdown races
Play all the maps in the game
Unlock the crocco
Avoid taking damage during a race
Make the bridge jump in Serpentine Valley