This is a really simple hack: it's barebones with no complicated obstacles. It's structurally varied but lacks challenge. Most of it can be passed by running and jumping, although there are some awkward swimming segments where you're blocked off by invisible music note blocks. Unlike classic Mario though, there's not even any secret to find within the levels.
Yoshi's purpose isn't clear to me, since the hack is already very easy. Since he and the blue shells are present in the first level, you can fly over much of everything.
The only ExGFX present in this otherwise vanilla hack will be the turkey you find at the very end of the second level. The setting of the hack is perfect for finding a turkey (i.e. innawoods) and the hack uses the Forest of Illusion submap. The paths are already revealed but you have to play the two levels in sequence, which I find to be a downside since it always looks neater to have paths be revealed.
Music breaks in the first level at the loop sometimes and other times you can hear a screech. In the second level, grabbing a star or spitting Yoshi's fireball will kill all sound and the game will crash when you die or go down a pipe.