Full list of all 49 Sonic Generations achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Completed the first stage.
Restored the GREEH HILL stage Gate.
Restored the CHEMICAL PLANT Stage Gate.
Restored the SKY SANCTUARY Stage Gate.
Restored the SPEED HIGHWAY Stage Gate.
Restored the CITY ESCAPE Stage Gate.
Restored the SEASIDE HILL Stage Gate.
Restored the CRISIS CITY Stage Gate.
Restored the ROOFTOP RUN Stage Gate.
Restored the PLANET WISP Stage Gate.
Defeated Death Egg Robot.
Defeated Perfect Chaos.
Defeated Egg Dragoon.
Defeated Metal Sonic.
Collected all the Chaos Emeralds.
Cleared Sonic Generations.
Cleared Green Hill within one minute.
Got Rank S in an act.
Got Rank S in acts three times.
Got Rank S in acts seven times.
Got Rank S in acts 12 times.
Got Rank S in all acts.
Executed a trick with a seven-step combo or longer.
Defeated 100 enemies.
Reached the goal without dropping any of the rings you collected in GREEN HILL Act 1.
Performed all of Sonic's actions in Act 2.
Took no damage while defeating the final boss.
Completed all of Sonic's friends' Challenges.
Chatted with all of Sonic's friends you saved.
Joined the rankings.
Participated in a 30 Second Trial.
Found the spring hidden in GREEN HILL Act 1 and reached the goal with a Red Star Ring.
Cleared CHEMICAL PLANT without entering the water.
Cleared SKY SANCTUARY without falling even once.
Got the Red Star Ring located on the shortcut route in SPEED HIGHWAY.
Wrecked 30 or more cars in CITY ESCAPE.
Got the Red Star Ring located in the hidden room in SEASIDE HILL.
Reached the goal in CRISIS CITY without being hit by a tornado-carried car.
Got the Red Star Ring atop the highest spot in ROOFTOP RUN.
Got the Red Star Ring by using an Orange Wisp in PLANET WISP.
Cleared a regular stage as Super Sonic.
Got all custom skills.
Got all collectibles.
Played Time Attack on all stages.
Got all Red Star Rings.
Cleared half the missions.
Cleared all the missions.