While it was the only installment to be released for the PlayStation, Castlevania: Symphony of the Night completely changed the focus of the series.
Previous games had been action-platformers, and progressed linearly from level to level; SotN introduced a Metroid-style map, with exploration and skill upgrades unlocking the ability to proceed further into Dracula’s castle.
And then, just when you think you’ve finished the game and the map is almost at 100% complete, they go and flip the whole castle upside down and you continue playing; the real goal is 200%!
Alucard, Dracula’s half-human son, is the protagonist, and after being stripped of his possessions and powers by Death in the game’s opening, has to explore the castle to regain his abilities and equipment, and fulfill his mother’s wish for him to protect humanity from his father.
While it’s more of an action game, it does have RPG elements; Alucard levels up as he fights enemies, and can equip better gear as he progresses through the castle.
And true to JRPG form, the game features some rockin’ boss music: