Full list of all 15 Mad Riders achievements worth 250 gamerscore. It takes around 10-12 hours to unlock all of the achievements in the base game on Xbox 360.
The base game contains 12 achievements worth 200 Gamerscore, and there is 1 DLC pack containing 3 achievements worth 50 Gamerscore.
Win your first race (Single player)
Win the last Tournament race (complete the tournament)
Win all races in all tournament cards including Offroad Elite races
Collect 100 boost tokens
Perform 250 Stunts
Perform 100 Stunts
Land in the target zone 50 times
Activate Recharge 66 times
Activate a Shortcut 50 times
Win all "Offroad Elite" events
Win a multiplayer race
Achieve level 10 in multiplayer
Achieve a 3-star rating in all "High Stakes" and "Balance of Forces" races
Reach driver level 15
Win 10 multiplayer races on tracks from "High Stakes" and "Balance of Forces" events