The music was really nice for this game, gotta love Sakura Sakura. Having the game keep track of your best score was a nice touch too, gave you some motivation to play more.
The attack animation was sluggish, I think speeding it up would feel better. I was also able to kill enemies that were clearly out of range of my sword. That part could use some work.
With some work on the graphics and maybe some additional features this could be a pretty fun game.