It's not a very well-polished game at all. That said, for a project someone made by himself in three months, it IS very impressive. The art needs work and the enemies more variety, but the core idea behind the game is solid, at least.
What I'd like to see in terms of REALISTIC improvements to what's here, beyond better spelling (I get the feeling that English isn't your native language, and fair enough), is more health pick-ups. I only saw one in the first level, after killing the boss, and I died not soon after. Either add more pick-ups or allow players to start at new levels if they die. I also activated the dash attack a lot when I just wanted to do normal slashes, though that may have been an error on my part.
This game isn't fantastic at all, but it shows tremendous promise. Keep at it!