Summary
Strangely... This scroller is completely perfect.
The Good
Oh, everything, but there's a common formula in use here. The long forgotten FUN = GOOD GAME! Today, the widely used formula is IMPOSSIBLE = FUN = GOOD GAME! Huh? Sure, it can get somewhat hard here, but who cares? It isn't a pain in the ass, and that's good. It simply focuses on a nice and long journey to defeat Bowser and his stupid, dysfunctional children, which are basically evil turtles with wands.
I can't really explain why this game is as good as it is. Perhaps it has to do with the fact that it is a classic, or merely the hours I would spend playing it. Someone just hit the nail on the head with the right hammer, I suppose.
The Bad
I like Sonic better. Much. Good. But this game is perfect on its own.
The Bottom Line
Perfection