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