I think this is a nice prototype you can build off of! The theme is well integrated and the visuals fit well, although I found some particle effects and visuals were too much. Your design language was well executed from menu to end-screen. The music was good, but the rest of the audio was a little lacking and too repetetive. The gameplay could be expanded upon, in the current state it's not really challenging. At some point, I just jumped over the hordes of enemies and ran to the boss and killed him. If you flesh this game out a bit more and make it more challenging, I could see this becoming a nice game. Good job!