It looks really pretty. But the game isn't playable for me. I tried various combinations but I wasn't able to use my sword. It also doesn't help that you don't provide a description in english (at least the keys could have been described there).
Besides that: once you press Y the previous music doesn't stop - but the background track is added again. This keeps on going and is really disturbing. I found out that hitting m silences the game and by pressing m again the track is there only once.
I finally gave up after pressing N which seems to kill the whole game.
Overall I couldn't see anything regrading the theme nor the limitation. I guess it was used later in the game - but unfortunately I wasn't able to reach that point.
So I would HIGHLY recommend to provide an english translation of the description. Even if it is just the keymap. That might will save you some ratings.