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.
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 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 CHEMICAL PLANT Act 2 without entering the water.
Found the spring hidden in GREEN HILL Act 1 and reached the goal with a Red Star Ring.
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.
Played Ranking Attack on all stages.
Got Rank S in all Acts.
Cleared all the Challenge Acts.
Completed all Challenge Acts featuring Sonic's friends.
Got Rank S in twelve Acts.
Wrecked 30 or more cars in CITY ESCAPE Act 2.
Got Rank S in seven Acts.
Cleared half the Challenge Acts.
Joined the rankings.
Participated in a 30 Second Trial.
Got Rank S in three Acts.
Cleared a regular stage as Super Sonic.
Cleared GREEN HILL Act 1 within one minute.
Reached the goal without dropping any of the rings you collected in GREEN HILL Act 1.
Got Rank S in an Act.
Cleared Sonic Generations.
Collected all the Chaos Emeralds.
Defeated Egg Dragoon.
Defeated Silver.
Chatted with all of Sonic's friends you saved.
Restored the PLANET WISP Stage Gate.
Restored the ROOFTOP RUN Stage Gate.
Got the Red Star Ring atop the highest spot in ROOFTOP RUN Act 2 and reached the goal.
Pulled off a seven or more trick combo or six trick combo ending in a finishing trick.
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.
Restored the SPEED HIGHWAY Stage Gate.
Defeated Death Egg Robot.
Defeated Metal Sonic.
Restored the SKY SANCTUARY Stage Gate.
Defeated 100 enemies.
Cleared SKY SANCTUARY Act 1 without falling and losing a life.
Restored the CHEMICAL PLANT Stage Gate.
Restored the GREEN HILL Stage Gate.
Completed the first stage.