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.
Achieve level 10 in multiplayer
Win a multiplayer race
Win all races in all tournament cards including Offroad Elite races
Win all "Offroad Elite" events
Activate Recharge 66 times
Win the last Tournament race (complete the tournament)
Land in the target zone 50 times
Activate a Shortcut 50 times
Perform 250 Stunts
Collect 100 boost tokens
Perform 100 Stunts
Win your first race (Single player)
Reach driver level 15
Win 10 multiplayer races on tracks from "High Stakes" and "Balance of Forces" events
Achieve a 3-star rating in all "High Stakes" and "Balance of Forces" races