Here is the full list of all 20 Steven Universe: Save the Light achievements.
Jump through a big donut
Defeat 100 Light Constructs
Perform 10 Perfect blocks in a row
Perform 10 Perfect attacks in a row
Complete all the Fish Stew Pizza deliveries
Help Vidalia finish her masterpiece
Receive every fortune from BOLTRON: SON OF ZOLTRON
Defeat any boss without letting any party members be defeated
Defeat three enemies with a single attack
Deliver over 100 damage with one ability
Perform every fusion and team attack
Experience an alternate sequence of events...
Save Light Steven and the Prism
Win the fight and then go out for pizzas!
Recover every Lil' Light Steven
Fully upgrade all weapons at The Forge
Defeat any boss while wearing the CBF Badge
Travel to every zone
Complete the game to 100%
Collect all other achievements