This is a rather generic hack that doesn't contain a story. It consists of unreleased levels from canceled projects (an unnamed project from 2008 and some levels from Super Mario's Legend - Vacations at the Tropics) and my Choco 2010, Vanilla 2011 and Vanilla 2012 contest entries, remade with new graphics and a few other features.
No custom music as promised in the trailer, I'm sorry. But the hack is done anyways - so I hope you have some fun playing here.
You can read the Readme for change log/known bugs reference.
Overall, it was fun, and the hard levels were able to catch my interest. Yes, it definitely started out easy and then got hard. The difficulty wasn't my main gripe, but it was actually the length. These levels had no midpoints, and at 7-8 minutes per endgame level, these levels could have used it.
That doesn't mean it wasn't hard. It was, and it was a good and legitimate hard. I played through the end to 100%, even if it shouldn't say 33 levels at the top. It should actually say 27, because you have to play 6 levels twice. It's like building a house, then tearing it down (line from AVGN).
I would say, carry over the verdict from my Let's Play of this and go with 75% once everything is taken into account. Play it, but don't bother going for 100%.