It is a truly exceptional and influential ROM hack, and it ages exceptionally well. It set the standard of quality for new, complete Mario games on the SM64 engine, and despite some annoying stars, it feels easily as accomplished as the vanilla game in terms of level design. There now exists many versions of this game, even one that is compatible with the N64 console of you own an Everdrive, and it feels as much like a fantastic add-on to SM64 as SMG2 feels like a fantastic add-on to SMG1. An excellent place to start if you have an interest for SM64 ROM hacking and don't know what to play first.