Vampire Killer is a game produced by Konami. Its original Japanese title is Akumajō Dracula (i.e Demon Castle Dracula or Dracula's Satanic Castle). The game's premise is the same seen on many Castlevania games. Simon Belmont ventures inside Castlevania to defeat Count Dracula and restore peace in the land of Transylvania. He fights his way through hordes of monsters, wielding only a whip.

This is the second game released in the Castlevania series. Akumajo Dracula (Castlevania outside Japan) was released for the Famicom Disk System. However, this is the first game in the series that was released outside Japan, which explains why some gamers think this is the very first release in the series. This game is seen as an “adaptation” of Castlevania, containing certain RPG elements and graphical upgrades.

Vampire Killer is seen as unique in the early Castlevania series for containing several features that weren't seen in other games that were intended to be remakes of the original game. For example, to progress in the game, it is necessary to acquire “skeleton keys” hidden in the several rooms within the game's castle, in order to open doors to other rooms. Other keys also have to be found in order to open treasure chests containing useful items, such as shields for protection and speed boots. Merchants can be found along the way (and mostly by breaking open walls with the whip), selling items to the player. While containing considerably different gameplay than the original Castlevania, both games share most of the same background settings, enemies and music.