Here is the full list of all 50 Sonic & All-Stars Racing Transformed achievements.
Do a Reckless Boost
Finish a Battle Race without losing any lives
Do a Boost-Start in each vehicle mode
Manually select a Random Character for a Matchmaking game
Hit an opponent with a weapon while looking backwards
Roll Left, Roll Right, Backflip, Forward Flip and land as a car or boat
Do 10 Stunt Combos in a single event
Beat your first Staff Ghost in Time Attack
Finish in 1st Place in all Grand Prix tournaments at Expert difficulty
Get a Podium Finish in every Grand Prix tournament on Expert difficulty
Unlock every Character in the game
Complete the Dream Valley Ring Race and pass every Ring as NiGHTS or Reala
Earn your Star License
Unlock Superstar Showdown in World Tour
Get 10 hits by firing weapons backwards in a single event
Earn your S Class License
Complete a World Tour event on Expert difficulty
Freeze an opponent using Ice from at least 100 meters away
Finish 1st in a Grand Prix tournament at Expert difficulty
Visit every location in the game
Get a Podium Finish in every Grand Prix tournament
Do a Level 3 Air-Drift
Earn your A Class License
Finish 0.5 seconds ahead of an opponent in a Race
Unlock Mirror Grand Prix mode
Score 90% accuracy with aimed weapons in an event
Triple-Stunt while transforming into a car or boat
Do 5 overtakes in a single Drift
Hit 1st, 2nd and 3rd place with a Swarm attack
Get a total of 20 hits with weapons in a Race
Earn your B Class License
Detonate the Hot Rod at the very last second
Hit 2 opponents with a single Hot Rod Blast
Finish 1st a Grand Prix tournament
Win a Matchmaking game
Evade or Block a homing-weapon 3 times in a Race
Do a 10 second Drift as Sonic
Collect 10 Stars in World Tour
Absorb a weapon with the Glove and fire it back at your attacker
Win any event with a Mod equipped
Level-up a character
Finish 1st in a Race without getting hit by weapons
Go All-Star!
Earn your Triple-Star License
Beat all the Staff Ghosts in Time Attack
Complete an event with 4 local friends
Beat 01:11.16 in Time Attack as Vyse in Rogue's Landing
Collect every Star in World Tour
Get a Perfect Drift score on any Drift Challenge event
Finish 1st, 2nd, 3rd and 4th with local friends in a 10 player Race