Here is the full list of all 20 ATV Drift & Tricks achievements.
You knocked down 100 riders with swerves
Finish a race 10s ahead of your nearest rival (single race - 'God' difficulty)
Reach a total of one hour in mid-air
Move from last to first in the final lap of a race with at least 5 opponents in 'God' difficulty
Play a ten-player game
Lap an opponent in a race with 5 or fewer laps
Do a double flip
Do a 5-second burn out… and win!
Do 750 wheelies
Do a wheelie on the Great Wall of China
Reach a total of 150,000 style points in one race
Win a league involving 4 or more races without falling once
Successfully perform 200 T.U.R.B.O landings
Score more than 800 points with a single trick
Do a Flip + Trick combo
Successfully attempt 50 T.U.R.B.O landings
Do a 250-meter drift
Reach a x10 style combo
Win a race
Beat all developers' times in Hot Lap