Full list of all 49 Sonic Generations achievements worth 1,000 gamerscore. It takes around 20-25 hours to unlock all of the achievements on Xbox 360.
Took no damage from the final boss and cleared the stage.
Got all collectibles.
Got all Skills.
Got all Red Star Rings.
Cleared all the Challenge Acts.
Got the Red Star Ring located on the shortcut route in SPEED HIGHWAY Act 2 and reached the goal.
Played Ranking Attack on all stages.
Reached the goal in CRISIS CITY Act 2 without being hit by a tornado-carried cars or rocks.
Got the Red Star Ring atop the highest spot in ROOFTOP RUN Act 2 and reached the goal.
Got the Red Star Ring located in the hidden room in SEASIDE HILL Act 1 and reached the goal.
Got Rank S in all Acts.
Cleared half the Challenge Acts.
Restored the SEASIDE HILL Stage Gate.
Cleared CHEMICAL PLANT Act 2 without entering the water.
Completed all Challenge Acts featuring Sonic's friends.
Cleared a regular stage as Super Sonic.
Cleared Sonic Generations.
Collected all the Chaos Emeralds.
Defeated Egg Dragoon.
Got Rank S in twelve Acts.
Defeated Silver.
Chatted with all of Sonic's friends you saved.
Restored the PLANET WISP Stage Gate.
Got the Red Star Ring by using an Orange Wisp in PLANET WISP Act 2 and reached the goal.
Restored the ROOFTOP RUN Stage Gate.
Restored the CRISIS CITY Stage Gate.
Defeated Perfect Chaos.
Defeated Shadow.
Got Rank S in seven Acts.
Restored the CITY ESCAPE Stage Gate.
Wrecked 30 or more cars in CITY ESCAPE Act 2.
Restored the SPEED HIGHWAY Stage Gate.
Performed all of Sonic's actions in Act 2.
Defeated Death Egg Robot.
Defeated Metal Sonic.
Restored the SKY SANCTUARY Stage Gate.
Joined the rankings.
Participated in a 30 Second Trial.
Cleared SKY SANCTUARY Act 1 without falling and losing a life.
Restored the CHEMICAL PLANT Stage Gate.
Defeated 100 enemies.
Got Rank S in three Acts.
Pulled off a seven or more trick combo or six trick combo ending in a finishing trick.
Found the spring hidden in GREEN HILL Act 1 and reached the goal with a Red Star Ring.
Restored the GREEN HILL Stage Gate.
Got Rank S in an Act.
Cleared GREEN HILL Act 1 within one minute.
Completed the first stage.
Reached the goal without dropping any of the rings you collected in GREEN HILL Act 1.