Here is the full list of all 12 Castlevania: Symphony of the Night achievements worth 200 gamerscore.
Defeat Gaibon and Slogra.
Finish the game, including the inverted castle, as Richter.
Explore 200.6% of the game.
Collect a bank of $100,000.
Unlock/Cast all eight of Alucard’s spells.
Defeat 10 consecutive enemies using special weapons without getting hit.
Defeat 10 consecutive enemies using only magic without getting hit.
Defeat Dracula in the Bloodlines stage without getting hit.
Unlock the Inverted Castle.
Collect all five familiars in the game.
Obtain the Bat, Wolf and Mist transformations.
Defeat 10 consecutive enemies using standard weapons without getting hit.