Here is the full list of all 38 Sonic Superstars achievements.
Defeated the true boss.
Cleared Trip's story.
Collected 100 Medals from Bonus Stages.
Turned super using the 7 Chaos Emeralds.
Used the White Emerald power "Extra".
Used the Yellow Emerald power "Slow".
Used the Green Emerald power "Ivy".
Used the Goal Plate to reveal the hidden Item Box.
Cleared a Stage with a friend.
Collected 200 or more Rings when clearing a Stage.
Cleared an ACT "Fruit".
Cleared all of EGG FORTRESS.
Cleared all of FROZEN BASE.
Cleared Zap Scrap in Frozen Base without taking damage.
Cleared all of CYBER STATION.
Cleared all of GOLDEN CAPITAL.
Used the Light Blue Emerald power "Water".
Cleared all of PRESS FACTORY.
Cleared all of SAND SANCTUARY.
Cleared all of LAGOON CITY.
Turned Lagoon City's Goal Plate into a pile of fruit.
Cleared all of PINBALL CARNIVAL.
Cleared all of SKY TEMPLE.
Used the Purple Emerald power "Vision".
Cleared all of SPEED JUNGLE.
Used the Red Emerald power "Bullet".
Cleared all of BRIDGE ISLAND.
Cleared 1 Bonus Stage.
Used the Blue Emerald power "Avatar".
Collected 10,000 Rings.
Used Sonic's Drop Dash to defeat 100 enemies.
Used Tails' aerial attack to defeat 100 enemies.
Used Knuckles' glide to defeat 100 enemies.
Used Amy's Hammer to defeat 100 enemies.
Used Trip's double jump to defeat 100 enemies.
Collected 600 or more Rings from ACT "Fruit".
Defeated 1,000 enemies.
Defeated the gold enemies in all Stages.