Here is the full list of all 38 Sonic Superstars achievements.
Defeated 1,000 enemies.
Defeated the gold enemies in all Stages.
Used Trip's double jump to defeat 100 enemies.
Used Tails' aerial attack to defeat 100 enemies.
Collected 100 Medals from Bonus Stages.
Used Knuckles' glide to defeat 100 enemies.
Used Amy's Hammer to defeat 100 enemies.
Used Sonic's Drop Dash to defeat 100 enemies.
Cleared Zap Scrap in Frozen Base without taking damage.
Cleared a Stage with a friend.
Collected 600 or more Rings from ACT "Fruit".
Collected 10,000 Rings.
Defeated the true boss.
Cleared Trip's story.
Turned Lagoon City's Goal Plate into a pile of fruit.
Collected 200 or more Rings when clearing a Stage.
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 all of PINBALL CARNIVAL.
Cleared an ACT "Fruit".
Used the Goal Plate to reveal the hidden Item Box.
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".