Neat little game. I liked the graphics and the pentagrams where you could 'buy' upgrades. Sometimes after getting resurrected, the enemy shots would just instantly kill you over and over. I had quite a few rooms that were empty, looks like the maps were procedurally generated which is pretty cool.
I did think is felt weird to move from the game to the Gameboy UI. Moving the mouse to press A after using keyboard in the game...kind of broke the 4th wall...so I guess you were ready for that potential theme as well. But it did feel a little awkward to press 'A' on screen.
Nice controls and lore text, I thought they were kind of amusing.