Trophies
     Complete each requirement to get the specified Trophy. 
There are 12 Bronze Trophies, 6 Silver Trophies, 7 Gold Trophies, 
and 1 Platinum Trophy.

Acrobat (Bronze):             Perform a two stunt combo.

Adrenaline Junkie (Bronze):   Stay in adrenaline mode for 30 seconds.

Backflip (Bronze):            Perform a backflip.

Berzerk (Silver):             Take down three opponents in a row 
                              without crashing.

Big Air (Bronze):             Stay airborne for 3 seconds.

Boostaholic (Gold):           Stay in adrenaline mode for 60 seconds.

Bully (Bronze):               Take down one opponent.

Crowdsurfing (Bronze):        Collide with the spectators.

Double Backflip (Gold):       Perform a double backflip.

Double Frontflip (Gold):      Perform a double frontflip.

Friendly (Bronze):            Invite someone to a race.

Frontflip (Bronze):           Perform a frontflip.

Frozen (Silver):              Hold a stunt for 4 seconds.

Hangtime (Bronze):            Hold a stunt for 2 seconds.

Head Splat (Silver):          Land on top of another player 
                              in an offline match.

Hoarder (Bronze):             Unlock half of all unlockables 
                              in career mode.

Online Acrobat (Gold):        Collide with the spectators.

Orbit (Gold):                 Stay airborne for 5 seconds.

Pack Rat (Silver):            Unlock all unlockables in career mode.

Platinum:                     Collect all other trophies.

Rampage (Gold):               Take down four opponents 
                              in a row without crashing.

Roadrunner (Bronze):          Lead a race from start to finish.

Stingy (Silver):              Collect $50000 in career mode 
                              without spending them.

Untouchable (Silver):         Win a career race with your sled intact.

Wire Fu (Gold):               Perform a three stunt combo.

Woodcutter (Bronze): Collide with 3 trees in a race.