Even if the GFX work is admirable, not everything is good: this hack mainly focuses on the aesthetics, since it's a remake of a very famous Mario game. Admirable, but the flaws in it are, like, endless: you can spot atleast one error in each level, may it be a palette error, a major cutoff, a glitchy BGs, and the likes.
As remake it's not very good either, since some of the mechanics got changed with else. An example may be the final battle with Bowser, or Bowser's traps on the overworld, the goal card... there are many and many mechanics the original had and that in the remake haven't been implemented. It's kind of sad, but it's understandable, mainly for the technology of the period this hack was made in.
Overall... it works decently, you can play it if you want, but honestly I'd prefer playing the original if I want to play some SMB3.