Here is the full list of all 38 Sonic Superstars achievements.
Used Sonic's Drop Dash to defeat 100 enemies.
Turned Lagoon City's Goal Plate into a pile of fruit.
Collected 600 or more Rings from ACT "Fruit".
Cleared a Stage with a friend.
Cleared all of EGG FORTRESS.
Cleared all of FROZEN BASE.
Cleared all of CYBER STATION.
Turned super using the 7 Chaos Emeralds.
Cleared all of GOLDEN CAPITAL.
Used the White Emerald power "Extra".
Cleared all of PRESS FACTORY.
Used the Yellow Emerald power "Slow".
Cleared all of SAND SANCTUARY.
Used the Green Emerald power "Ivy".
Cleared all of LAGOON CITY.
Used the Light Blue Emerald power "Water".
Cleared an ACT "Fruit".
Cleared all of PINBALL CARNIVAL.
Used the Goal Plate to reveal the hidden Item Box.
Used the Purple Emerald power "Vision".
Cleared all of SKY TEMPLE.
Cleared all of SPEED JUNGLE.
Used the Red Emerald power "Bullet".
Cleared all of BRIDGE ISLAND.
Collected 200 or more Rings when clearing a Stage.
Cleared 1 Bonus Stage.
Used the Blue Emerald power "Avatar".
Cleared Trip's story.
Defeated the true boss.
Collected 10,000 Rings.
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.
Defeated 1,000 enemies.
Defeated the gold enemies in all Stages.