This is very close to being pure effing bliss! I had been hoping for something like that for a while, and I'm really glad it now exists. BUT it's far from being perfect for the following reasons:
-i would have loved a fully-fledged application, not a flash/director/whatever application with a crappy icon
-the window of the application is sometimes "transparent", i.e. you will be in finder with the app window right behind the folder window you're looking at, and clicking inside the finder window will add notes on the app's music sheet window behind it (??)
-it consumes a lot of CPU for an app that used to work on a Super Nintendo (and in a fuller version on nintendo than here!) (maybe making it a non-director app would solve that?)
-if you're gonna run this kind of program on a computer, maybe the best idea of them all would be to add a feature that couldn't have been available on a SNES cartridge: the Save function (or Export), you know, so you can send it to a friend, create a file, not just save it within the application where you only can enjoy it
-exporting sheet music or saving the project to be able to have multiple projects at the same time and go back to rework them would definitely be a plus as well
-maybe some shortcuts would be nice? Usually the space bar plays and stops on mac computers, and I think it wouldn't hurt to add this as well.

That said, I believe the programmer's only wish was to bring the music composer from MP onto the Mac at any cost, which they did, and at least the app doesn't crash and does what you can expect from it. Adding the little modifications stated above, though, would rank it among the best freeware apps of the mac for creative (and retarded) mac people like me.