Vampire Killer is a videogame created by Konami for MSX computers and released in 1986. It's been defined as an alternative version of Castlevania, released one month before, for the Famicom.
The two games, developed in parallel, are set in the same horror universe and share the same hero: Simon Belmont. Vampire Killer has some differences in terms of gameplay. While Castlevania is more linear, the MSX game designed by Akihiko Nagata requires more exploration and requires the player to find a key to exit each level. Due to the technical limitation of MSX computers, instead of horizontal scrolling, the screen flips when the hero reaches the border.
Vampire Killer didn't reach the same popularity as his twin, but it's still a classic, and if you haven't played until now, it's time to do it. GamesNostalgia offers it already packed with the MSX emulator. Enjoy!