I played this hack today in a quick session. First, i must say that i enjoyed this hack, but it has still some difficulties. The 2 posters under me have sayed that there are 2 level you can not acces,which is kind of strange because you can still see them on the overworld. It would be really cool if you would have changed the pallete of some levels, but thats sadly not the case. As conclusion i would say, that you still need some practice in hacking, but the hack is definitly playable and kind of enjoyable.
I started a new game on the 1st profile slot and when it showed the overworld it played the "death sound" and didn't show mario at all then when I press Y on the overworld I enter an endless bonus stage. So that must be a glitch.
I then tried on the second game slot and it worked just fine.
Played on real hardware.
Also kind of odd that you can enter all levels from the start. Some paths are strange because even though you can see the path you can't travel on that path.
Also there is one level where you climb on a hill you enter, but you can also enter the same level by walking to the right on it, which means that Mario just climbed a mountain without climbing.
On the overworld map it looks like there are 2 levels that you cannot even get to.