Just finished playing through it, honestly I love the project as a concept, there were a few issues with the camera not panning down enough, but honestly that just added to the gameboy soul (the limited screen size and etc).
Also the use of your head as a weapon AND as HP is a really good idea, if this were released back during the gameboy era, this could potentially be a "souls-like" game of that era simply due to how strategic you have to be in regards to enemies as well as making sure you don't die.
All in all, really good submission, almost lost my head ;)