Nice raycasting game! An English translation would have been nice, even though starting a new game is easy enough. For some reason fullscreen didn't work for me, the game played in the top left quarter of my screen. It's a bit difficult too, I couldn't survive more than a couple of flying heads, so I don't know if it's a long game or not. I'm betting it's quite long, since you seem to have a save/load system.
Nice work!