It has very good potential, only if author would have patience to finish the game, make it longer and perhaps improve graphics and animation. Boss fights are supposed to be hard, it would be pointless if you can beat it at first try. It took me two tries and thats good for first boss. Idea is pretty similiar to metroids and "metroidvanias" (if you know what I mean). And boss will be easier if you pick the strongest sword. Engine was simple and solid. But should definitely have more to it. 6/10