Here is the full list of all 33 MX Nitro achievements.
Collect all Track Quest's marks.
Speed up to 180 km/h on Drag.
Get and equip Enforcer set.
Finish a race with 108 seconds time.
Buy all bikes.
Get full Nitro Tank 100 times on Desert tracks.
Crash 300 times.
Overtake a total of 100 riders.
Drive 1000 seconds on rear wheel.
Win a ranked race.
Perform Superman 50 times.
Win a race with a half-wheel lead.
Get level 3.
Spent a total of 5 minutes in midair.
Buy and equip a new customization item.
Made a flashy finish.
Complete the First Tournament.
Take First place in any race.
Rode to finish without crashing.
Complete 50 challenges.
Perform only Fresh tricks in Freestyle and win.
Collect all stars in Online Race.
Perform all 4-button tricks in the game at least once.
Get 5000 Trick Score in one combo.
Fly 200 meters in one crashflight.
Found his Doom.
Earn a total of 50000 credits on Slums races.
Hoard 500 000 credits.
Beat Pedrolino.
Beat Punk Lizard.
Beat Steelhead.