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