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