Tip: Switch palace switches normally disappear if you replay the level. However, if you insert them as direct Map16 and use the hex-edit at $00EEB2 in the ROM map, you can replay the level without a problem.
What did my eyes just see? No offense, but I don't think this hack is so "greatest" after all.
The design is weird. Sometimes it's decent, with a good design, but some others it's either too flat or generally very bad because of the many flows that are in it. There is no asm here, everything has been based on GFX; while I was intrigued by the gimmicks and the mechanics, the design still kept at low levels. There are lots of levels that have a flat land with enemies placed randomly on it. Some others are, instead, kinda frustrating, like the last castle, which is extremly long and sometimes you're unfairly hit. I hated the Magikoopa's section, that was probably the worst section of the last castle. The difficulty curve is extremly silly: it's unbalanced, since some late levels felt easier than some former ones. It feels pretty weird. Anyways, as overall, I appreciate the lenght, but most of the levels felt rushed in design. I'd prefer a 1 level hack with good design rather than this honestly.
Here we go, aesthetics... where do I start? There is a lot to say about this. I saw so many games in this hack that I don't know if there's a style that defines it. Maybe not, since you used cartoony-ish gfx with realistic gfx with nes gfx with gb gfx and so on. The only problem isn't clashyness though, since there are lots of palette messes, bad gfx assembling that eventually made huge cutoffs and very bad-looking FG/BG in general. This is probably the worst hack I've seen aesthetic-wise.
Some other technical issues I found:
- One of the pipes in "Bowser's Island 3" and "Sub-City 2" leads you to an endless bonus game room.
- "Mt. Fuji" is almost unbeatable: it's impossible to proceed after the midway point, since there are too many sprites and the Yoshi won't always appear.
- "Cliffside Estate" makes you able to bring Yoshi in the battle with Wendy. His tongue gets glitchy, and you're also able to eat Wendy. Although that makes you stuck and you're forced to die.
- In "The cave of FootMen" you can die unfairly at the beginning due to a silly slope set.
- "Space Pirate Tavern" apparently it's supposed to have a secret exit, but there is none.
- Slowdown here and there and some major sprite tile limits errors. Sometimes, some sprites become invisible due to it.
That's it, overall, one of the worst hacks I've ever played.