Castlevania is a typical platform game of the 8-bit era: the game comprises six levels, which are played through in a strictly linear progression. The player controls Simon Belmont, whose primary mode of attack is via his whip, which can be upgraded by obtaining special items throughout the course of the game which extend its length. In addition, various "sub-weapons" can be obtained which provide different means of attack. By breaking candelabra and certain other items located throughout the castle, Simon collects hearts, which can then be used to activate whatever sub-weapon he possesses at that point. Simon can only carry one sub-weapon at a time.
Each of Castlevania's six levels conclude with a boss fight: these bosses are generally taken from horror literature or legend, and include a vampire bat, Medusa, mummies, Frankenstein's Monster and Igor, and the Grim Reaper.