Castlevania is a series with heritage. Since its introduction in 1986 it’s rarely skipped a year, with 40 released titles spanning consoles, PCs and arcades…
Castlevania is a lot of fun, and it’s evolved since ’86, as the source says, with enough titles to keep you busy as a fan; they’re release an average of about 1.5 games a year, –so you’ll have something Castlevania to play regardless. The source article is about the evolution of the Vampire Killer theme, as it has made its way through the most popular Castelvania titles over the years.
If you haven’t played the latest games in the series, check them out, –and also, bear in mind the differences in the theme music as you go along. Each tune more complex, but just as fun as the original.