Like in Castlevania, the player controls vampire hunter Simon Belmont, who ventures into Dracula's castle armed with a mystical whip inherited from his father, in order to slay the evil count.

While Vampire Killer shares the same premise, soundtrack, characters and locations as the original Castlevania, the structure of the game and its play mechanics differ significantly from its NES counterpart.

Items and weapons can be obtained by breaking through candle stands and certain walls like in the NES version, and by purchasing them from merchants hidden throughout the castle or by unlocking treasure chests using keys.

There are four items that Simon can carry with him similar to the sub-weapons in the NES version: a map which shows his current position and the location of the exit (can only be used three times), holy water, an hourglass (which temporarily paralyzes all enemies) and one of two types of shields.

The problem is that this attempt to create a sort of action-RPG hybrid is badly undone by its non-linear structure (which involves searching looping levels in order to find keys) and the MSX2's infamous inability to handle smooth scrolling – screens 'flip' from one to the other when you reach the edge of a room.