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