Solius: The Magic Castle
Solius is a 2D side-scrolling platformer game. It is styled after the classic games like Castlevania, Mega Man, Ninja Gaiden and Monster World, and the gameplay and art-style are patterned after being a Super Nintendo game but with a high-resolution modern display.
In the game you play as a knight inside a magic castle filled with monsters and demons. Inside the castle there are magic doors that take you to all sorts of different places and environments. As the player you must venture through the castle to defeat all the evil forces that have taken residence there, along the way collecting powerful items that will aid you in this endeavor.