Here is the full list of all 11 Back to the Future - Episode 3: Citizen Brown trophies - there are 5 bronze, 5 silver and 1 gold.
Layout Biff and escape the speakeasy.
Jumped into the Decycling Bin.
Got caught with Lorraine's booze.
Got caught with Einstein.
Got caught making out with Jennifer.
Listen to all tourist audio guides in Hill Valley.
Use the DeLorean parts to enter Hill Valley.
Collect every Demerit in the game.
Use the spray can to paint Marty's band name in the alley.
Examine every container of contraband in the speakeasy.
Coax Edna out of the courthouse with the buzzer.