You might think that the original Castlevania was one of the pioneers of the "Metroidvania" genre of games. This is wrong. The first game in the series was actually a humble platformer, and it is actually pretty well-designed. It revolves around Simon Belmont navigating Dracula's castle to ultimately defeat the series big bad. The controls are not agile, but it handles this quite well by giving players the tools needed to adapt to different enemies. It does so by giving players weapons that could be effectively used against the upcoming enemies. Not only is Simon's whip, known as the Vampire Killer, easily understood, long-range, and able to be used when crouching, the game also provides secondary weapons that can make quick work of otherwise annoying enemies when used properly. In short, this game is a platformer that derives its challenging gameplay from learning how to proficiently use the tools provided to defeat the hordes of enemies encountered on the journey. Pick this one up if you want something challenging.