Here is the full list of all 51 Sonic & All-Stars Racing Transformed trophies - there are 42 bronze, 5 silver, 3 gold and 1 platinum.
Get 10 hits by firing weapons backwards in a single event
Win a Matchmaking game
Manually select a Random character for a Matchmaking game
Earn your Star License
Complete the Dream Valley Ring Race and pass every Ring as NiGHTS or Reala
Unlock Superstar Showdown in World Tour
Hit 1st, 2nd and 3rd place with a Swarm attack
Complete a World Tour event on Expert difficulty
Do 10 Stunt Combos in a single event
Do a Boost-Start in each vehicle mode
Finish 1st in a Grand Prix tournament at Expert difficulty
Earn your S Class License
Get a Podium Finish in every Grand Prix tournament
Visit every location in the game
Get a total of 20 hits with weapons in a Race
Unlock Mirror Grand Prix mode
Evade or Block a homing-weapon 3 times in a Race
Do 5 overtakes in a single Drift
Roll Left, Roll Right, Backflip, Forward Flip and land as a car or boat
Triple-Stunt while transforming into a car or boat
Beat 01:11.16 in Time Attack as Vyse in Rogue's Landing
Do a Reckless Boost
Earn your A Class License
Hit 2 opponents with a single Hot Rod Blast
Score 90% accuracy with aimed weapons in an event
Absorb a weapon with the Glove and fire it back at your attacker
Finish 1st in a Race without getting hit by weapons
Do a Level 3 Air-Drift
Beat your first Staff Ghost in Time Attack
Hit an opponent with a weapon while looking backwards
Earn your B Class License
Finish 1st in a Grand Prix tournament
Finish a Battle Race without losing any lives
Detonate the Hot Rod at the very last second
Collect 10 Stars in World Tour
Win an event with a Mod equipped
Level-up a character
Go All-Star!
Finish 0.5 seconds ahead of an opponent in a Race
Do a 10 second Drift as Sonic
Earn every Trophy in the game
Earn your Triple-Star License
Beat all the Staff Ghosts in Time Attack
Unlock every Character in the game
Get a Podium Finish in every Grand Prix tournament on Expert difficulty
Survive a Twister attack without crashing or being hit
Collect every Star in World Tour
Get a Perfect Drift score on a Drift Challenge event
Freeze an opponent with Ice from at least 100 meters away
Finish 1st in every Grand Prix tournament on Expert difficulty
Raced in an ad hoc or Online game with Sonic, Tails, Amy, Shadow and Knuckles in the same race.