As far as content is concerned, it's the definitive version of SMB. Not only does it have the original game and Lost Levels, but it even comes with a "You vs. Boo" racing mode & a slew of bonus challenges to accomplish like Red Coin collecting & searching for Yoshi Eggs. At the end of the day, though, that GBC aspect ratio holds it back from being the titan of SMB1 versions it could otherwise be. Still a very fun & nostalgic game for me personally.