Sword Art Online: Fatal Bullet has multiple endings, each leading to the actual True End of the game. But getting each ending will help you unlock achievement before you start the New Game+.
There are three endings, two bad and one good. To get the true ending, you must first achieve the bad endings.
Once you get the two bad ends, rush through the game to complete the requirements to unlock the true ending. For each bad ending, you will get an achievement.
How to Get the Bad Ending?
To get the bad endings, you must choose to save Kureha in the final mission in SAO Fatal Bullet. This will end with Zeliska dying and give you a bad ending.
How To Unlock the True Ending?
To get the true ending, you must have all the original SAO Fatal Bullet members (Arfasys, Kureha, Zeliska, Itsuki, and Bazalt Joe) at Affection Level at 4 with 75%. Once this is done, have the original SAO characters like Kirito, Asuna, Primiere, Sinon, Philia, Rain, and Strea at Affection Level 2, and make sure you have watched all their event scenes.
Now, get the Afasys Amulet after clearing the Kirito Mode. Ensure you don’t pass to the next Main Quest, which will appear right after Kirito Mode. After getting the Amulet, fighting the final boss, and evading its hyper beam, the quest will change from Dead All to Fatal Bullet when you equip the Nervegear. This indicates that you are on your way to the True Ending.
