This game is really fun to play and in my opinion should be normal and not easy. The level design is really good and It looks like something Nintendo would make! The story is also good and the secret exit isn't too hard. I gave it 5 stars.
The design is okay, it's a traditional one, without too many shenanigans going on but still enjoyable. Good thing each level is varied enough to not be too monotonous. As said already it's an easy one, which slowly gets challengy, but not too much. Not much more to say; for how linear this was, it's still okay for me.
Aesthetic are good overall: except the overworld, which has lots of perspective errors, the rest is okay, the author uses nothing but vanilla resources, sometimes making palette edits too. Maybe there's a lack of decoration in general, but nothing too bad.
As only technical issue worth of mention, music breaks on accurate emulators. There is also some sprite tile limits issues, occuring in the ghost house, in the fishing boo part.
Overall, a good hack. Worth a shot if you're searching for easy hack inspired to SMW's way of designing.