Here is the full list of all 12 JoJo's Bizarre Adventure HD achievements worth 400 gamerscore.
Win one Ranked Match over Xbox LIVE.
Upload replay data.
K.O. N'Dool via Perfect in bonus stage.
Win a fight with 22 different characters.
Raise Mahrahia's magnetic power to maximum level.
Counter a time-freeze.
Activate a Blazing Fists match.
Down an opponent while they are Stand Crashed.
Down an opponent while in child form.
Down an opponent without using a Super Combo or Tandem Attack.
Complete Story Mode or Challenge Mode for any character on any difficulty without using continues.
Down an opponent with a Super Combo.