Bloodstained and Castlevania
Last updated . Sources are linked in the text.
Bloodstained: Ritual of the Night is a related recommendation, not a licensed Castlevania crossover. Its exploration-focused action RPG structure is the useful comparison for Symphony fans.
What Ritual of the Night offers
Developed by ArtPlay and published by 505 Games, Ritual of the Night released on PC on 18 June 2019. Koji Igarashi leads this separate exploration-focused, side-scrolling action RPG.
The protagonist is Miriam, affected by an alchemist's crystallizing curse. Castle exploration, equipment and upgradeable weapons and spells are the relevant similarities; this is not a game starring a Belmont.
Which Bloodstained?
This recommendation is specifically Ritual of the Night. Inti Creates' Bloodstained: Curse of the Moon is a different, retro-style action game. Its title is not an alternate name for Ritual of the Night, and buying one does not imply the other is included.
It has its own world and is outside Castlevania's chronology. There is no Castlevania base-game requirement, and it is not included in Anniversary, Advance, Dominus or Requiem.
Official source
ArtPlay / 505 Games Steam listing: developer, publisher, Miriam and gameplay. The comparison is editorial; shared creative lineage is not shared canon.
Questions
Is Bloodstained a Castlevania sequel?
No. It is a separate ArtPlay series, published by 505 Games.
Which title matches castle exploration?
Ritual of the Night is the exploration-focused side-scrolling action RPG discussed here.