Here is the full list of all 30 Guilty Gear XX Accent Core Plus achievements worth 400 gamerscore.
[Ranked Match] Fight 100 battles.
[Story] See all endings.
[Player Match] Fight 100 battles.
[Ranking Match] Won 10 in a row.
[Ranked Match] First victory attained.
[Player Match] First victory attained.
[Survival] First intrusion occurred.
[M.O.M] Defeat Order Sol and complete.
[M.O.M] Complete it.
[VS CPU] Won against CPU on difficulty level MANIAC.
[Arcade] Completed in difficulty level MANIAC
Successfully execute your first throw escape.
[Story] Saw one ending.
Throw a chikuwa and dumbbell at your opponent.
[VS 2P] Battled offline.
[Mission] Complete all missions with any character.
Even with a huge difference in health, you came from behind and won.
[Mission] Complete 5 mission with any character.
[Arcade] Defeat Order Sol.
You scored your first instant kill.
[Arcade] Completed.
Game started.
[Survival] Reach Lv. 999 and defeat Gold Order Sol.
[Survival] Select Time Traveling skill 3 times in a row.
[Survival] Equip skills Berserk Mode and Limit Break and complete.
[Survival] Complete Classic Survival.
[Training] Train for over 10 hours.
Get all character illustrations.
Fight on all stages.
Make contact with an alien.