Here is the full list of all 28 Arcade Spirits: The New Challengers achievements.
Romance nobody.
Complete all romances.
Romance the Rival.
Enter the finale while Quirky.
Romance Locksley.
Romance Zapper.
Enter the finale while Gutsy.
Romance Jynx.
Encourage Iris to be Chaotic.
Romance Grace and Jynx.
Lose all three major FoD2 matches.
Romance Domino.
Romance Rhapsody.
Enter the finale while Steady.
Mixed wins and losses in major FoD2 matches.
Romance Grace.
Encourage Iris to be Orderly.
Clear Level 8.
Perform the Ultimate expression of pizza on a bagel.
Enter the finale while Kindly.
Clear Level 7.
Clear Level 6.
Win all three major FoD2 matches.
Clear Level 5.
Clear Level 4.
Clear Level 3.
Clear Level 2.
Clear Level 1.