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