Pachislot Akumajou Dracula

Being a pachislot with vaguely connected cinematics occurring randomly during play, the game has no coherent narrative like more traditional games in the series. These cutscenes exists to tease the player, but contain little actual story content. However, going by comments on the official developer's blog, the game does tell a story, although most of it requires the player's imagination to fill in the blanks.

On the blog it's written the game is "another story", a term sometimes used to imply the setting takes place in a parallel world or alternate universe. Because the game is mainly based on Castlevania: Curse of Darkness some of the characters resemble their incarnations from the IGA continuity. Together with Pachislot Akumajō Dracula II, it tells the same story of Trevor fighting Count Dracula, who has been revived with the assistance of Angela.

It should also be noted that from the brief interactions between Trevor and Dracula, it's implied they already share a past. This would be further explored in Pachislot Akumajō Dracula III, which is a prequel to the previous two games.

Pachislot Akumajou Dracula is a pachislot game created by Konami Parlor Entertainment. Its aesthetics are based on Castlevania: Curse of Darkness and features most of its cast, including Trevor Belmont in the leading role. The game functions like a slot machine but also features cinematic scenes.
A sequel, Pachislot Akumajou Dracula II, was released in 2010. It features much the same cast as the original game, which is based on the cast of Castlevania: Curse of Darkness and Castlevania: Lament of Innocence.
It was followed by Pachislot Akumajou Dracula III in 2012. It features much of the cast of Castlevania III: Dracula's Curse, including Trevor, Alucard, Sypha, Succubus, Doppelganger and Dracula.