Good but...
It needed some more things in it, especially a health bar for the 'Mushmon'. I sat there fore way too long just hitting it and dealing what looked like heaps of damage only to see nothing happen, maybe I was doing something wrong but still.
I really like how good it looked and it ran pretty sweet, I think maybe you should add a few levels in or something to build up to the fight, I'd love to see that. Music would be good too, even just an epic song would be pretty cool for the fight.