I'm not one to argue, but I do just want to clear up the obvious misunderstanding. I'm not saying that it's not cool to change it up and do your own rendition - just the contrary, I am pretty well known by my colleagues for reharmonizing alot. What I will contend, however, is that if you are going to reharmonize something, it still has to work. The melody and changes should not disagree so drastically, unless you're deliberately going for a dissonant and cacophonous sound, which I do not think is the case here. In any event, I just feel like reharmonizations should be more interesting or intriguing than the original in some way. I just happen to find the original Nintendo version more interesting and complex both melodically and harmonically.