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