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