Here is the full list of all 50 Moto Racer 4 achievements.
Find all the shortcuts in the game
Succeed all the slalom challenges with 3 stars
Do a double flip
Reach a total of 500,000 style points in one race
Score more than 800 points with a single trick
You knocked down 100 riders with swerves
Upgrade the T.U.R.B.O on Jody and Saul's bikes to the max
Do a 250-meter drift
Ride on a truck's trailer
Succeed chapter 5
Do a 10-turn donut
Win all races in the 6-5 Championship with Amund
Upgrade Wrench and Bolt's bikes to the max
Customize Stella to the max
Win the 6-2 challenge with a Gold performance
Do 3500 wheelies
Reach a total of one hour in mid-air
Successfully perform 200 T.U.R.B.O landings
Do a wheelie on the Great Wall of China
Score more than 5 000 000 style points
Successfully attempt 50 perfect landings in one race
Brush against vehicles in traffic 300 times
Successfully attempt 200 orange T.U.R.B.O boosts
Move from one bridge to another over Spider Gorges
Reach a total of 180 seconds of slipstreaming during a race
Reach a total of 150,000 style points in one race
Do a Flip + Trick combo
Do a 5-second burn out… and win!
Win the 3-3 challenge without using the turbo
Perform a whip on a dirt bike
Win 100 races online
Score 3000 high-speed points in one go
Make 100 online opponents fall down
Keep your light trail for 120 seconds
Do 250 wheelies
Reach a total of 50,000 style points in one race
Reach a x10 style combo
Succeed a challenge
Win a ten-player online championship
Win a ten-player online game
Do a trick
Land on an opponent and make him or her fall down
Finish a private online game
Play a ten-player game
Unlock the eleventh chapter
Unlock 165 stars
Succeed 55 challenges
Do 200 swerves
Win the 9-3 challenge with a Gold performance
Finish a race 10s ahead of your nearest rival (single race - 'God' difficulty)