Here is the full list of all 15 Bloodstained: Curse of the Moon achievements worth 1,000 gamerscore.
Defeat every boss in Boss Rush mode.
Finish the game without sacrificing or recruiting any adventurers.
Go it alone and see the Normal ending.
Adventure with your allies and see the Normal ending.
Finish Nightmare Mode.
Sacrifice every adventurer and finish the game.
Recruit every adventurer and finish the game.
Finish Stage 8 for the first time.
Finish Stage 7 for the first time.
Finish Stage 6 for the first time.
Finish Stage 5 for the first time.
Finish Stage 4 for the first time.
Finish Stage 3 for the first time.
Finish Stage 2 for the first time.
Finish Stage 1 for the first time.