very nice game! Boris feels kinda clunky when using the sword, but that may just be me. I couldn't really understand what was happening in the intro, but after reading how the theme was integrated, it makes more sense. soundtrack was nice! there was one moment where my game froze for a second, but then came back. no idea what caused it. this may just be a personal preference thing, but having maybe a count of how many enemies there are in a room that need to be slain to go to the next room would be better than just being randomly teleported to the next one. I got a little confused after I didn't go to the right side of the screen to go to the next room.
tl;dr, good work!