Graphically, it is a rather mixed bag. You've got vanilla here, rips there, and original graphics spread about. There isn't really much of a consistency to be honest. Aesthetically, the hack doesn't really make great use of these assets either; a lot of levels end up feel flat and bland, and I've seen quite a bit of cement block spam in some places too. I guess the worst offenders here are the "purple" zone palettes, which are just monochromatic, oversatured and do nothing about the wite highlights on pipes and other objects; it's not pretty to look at.
I should also mention Jerry specifically as a graphical issue, because he does not change at all when he picks up a powerup; his "small" form is identical to his "big" form, so you have no idea whether you can actually withstand a hit or not. There -is- a slight color difference on Jerry's stem when you pick up a fire flower but again, it's difficult to notice. This hack really could've benefitted from some kind of status indicator, considering the author went to lengths to incorporate some ASM here.
The music, aside from the fact it breaks on accurate emulators, also seems to have some quality issues. Case in point, the port of the Yoshi's Island cave theme sounds really messed up and I have no idea how that happened when there have been perfectly good renditions of it on this site since even before 2010.
Some tools and hex edits were clearly used in this hack, as the status bar is changed from usual, disabling the item reserve box (though why is the word TIME missing from the timer?) cape flight is disabled, and teleport blocks get used here and there. As I mentioned earlier, there really should have been a health indicator, and it also would have been nice if bosses had a visible health counter, as most of them take a lot of hits to defeat.
I also noticed VWF cutscenes were used in a few places, but before the final boss battle, you get a "vanilla" cutscene where the player presses up to enter a hidden door to proceed. Very odd inconsistency there...
Onto the gameplay, it's pretty weak. The traditional platforming levels are just really lacking in obstacles, often being rather flat, lacking in landform variety and population with enemies that don't serve much purpose beyond existing. Nonstandard levels like the Marine Pop stage and the enemy gauntlet rooms are poorly designed, with the former being a rather boring "don't touch anything that moves" maze and the latter consisting of serious enemy positioning issues resulting in cheap hits or make clearing more difficult than it should be.
Bosses deserve their own mention simply because there are far too many of these n00b bosses that do nothing but sit there and throw hammers, all the while you just keep throwing the blue blocks from outside of their range. Giving them more health does not make them harder, it just prolongs the inevitable outcome of the player eventually defeating the boss because the boss can't really hurt any player smart enough to stay away from the hammers.
Overall, I understand this was probably wasn't meant to be a serious attempt at a hack, but it still feels sloppy when it's played, and whatever this hack was supposed to be based off of is lost without the greater context of it all.