Here is the full list of all 12 Starstruck: Prologue achievements.
Get an A RANK or higher on Inside These Walls on Master Mode.
Get an A RANK or higher on Inside These Walls on Normal Mode.
Get an A RANK or higher on Enter Ozwald on Normal Mode.
Get an S RANK on any song.
Get an A RANK or higher on Break the Mold on Normal Mode.
Get an A RANK or higher on One Small Step on Normal Mode.
Get an A RANK or higher on Children of the Moon on Normal Mode.
Get an A RANK or higher on Children of the Moon on Master Mode.
Clear the main story of Starstruck: Prologue.
Get an A RANK or higher on Break the Mold on Master Mode.
Get an A RANK or higher on Enter Ozwald on Master Mode.
Get an A RANK or higher on One Small Step on Master Mode.