Good, yet glitches.
Let me start off by saying this is an awesome, original, kick ass game. I don't know how some people can seriously get off calling this 'unoriginal'. There is not a single game like this that I can think of.
Anyway, when battling bowser, there is a glitch I've encountered two of the ten or so times I beat the game. Bowser, instead of his rapid fire flame attack, he will begin to jump, and do his rapid fire flame attack at the same time. Yet this apparently triggers some glitch where every time he shoots flames, instead of shooting one flame every half a second or so. He shoots flames in large quantities of 10-20 or more at a time. Creating several walls of flames, which instantly kill mario.
Besides that though, once again. Excellent game!