I played this hack roughly a week before the end of the Vanilla Competition. while I really liked the ideas presented in this Hack, I felt it was lacking in some major areas.
Tails, clearly you have a lot of innovation; this is a quality that ranks above all others when it comes to game design. Every level felt fresh and enjoyable, yet you seemed to rely very little than the bare mechanics of the original game. For this I applaud you, and I recognize you as one of my favorite hackers in a very long while.
That being said, It seems that the entirety of your creative efforts was spent on one thing- visuals. While I did have a lot of fun, most of what I found to be entertaining was simply eye candy. You have a fresh visual style, and, judging by this years vanilla contest entries, the freshness of this style is going to be very short-lived. (I've posted that parody screenshot like 30 times already, but here it is again:
THIS is what has happened to your design style, thanks to that wonderful thing called imitation)
The truth is, every obstacle or gameplay mechanic presented in this hack has already been done. Normally, this wouldn't even be an issue for me (the above fact is true in 99.99% of hacks), but it seems you have the potential to do something more. Very few hacks have ever been created that, when played, left everyone in a state of shock. This effect has been harder and harder to do as hacking has evolved, but there is still uncharted territory to explore. Strip away the pretty visuals, and this game, like almost all others, shares the same old ideas as almost every hack before it.
So, how does one improve on this? Clearly I can't give you a straight answer to improve on my critique- all I can do is offer my personal design philosophy, in tandem with what I personally have seen to have worked. The rest of this post may or may not be completely worthless to you. I don't claim to be some sort of pro-hacker, but I can try my best to help:
From what I can see, there are two fundamental skills required to make fun gameplay. First and foremost, you have to be able to loosely plan out what you want to do with your level BEFORE you start working on it. Truly good levels are comprised of a series of short gimmicks. The level gives you a short taste of something fresh and interesting, and moves on to something else. This is not to be confused with the 'single-gimmick', brutal mario style of design (make as many variations of the same idea as possible, then line it all up in a level); we as humans are victim to the accumulation of tollerance- nothing is as good as it was that 'first time'. A level must strive to string a series of 'first times' together, thus maximizing the level of interest the player will feel. Doing this takes planning- you have to brainstorm to think of new gameplay mechanics. rearranging blocks will never be as effective as simply taking the time to think outside the box. Find some of these ideas that complement eachother: one concept should lead to the next, without ever repeating itself (the best extremes I can think of to exemplify this concept are Wario Ware and, again, Brutal Mario)
The second skill is that of balancing planning with Improvisation: Don't make a level look too formulaic in design. Games like Master Courses and WTH take this idea to the extreme- there is a very chaotic sense of development going on; while both are saturated in creativity, no order whatsoever causes confusion for the player, an unbalanced difficulty curve, and a lack of visual appeal.
I really don't know if this will help you, but I figured I'd help as much as I could. Hopefully there will be some benefit in posting this, even if that only benefit is "LOL U R IDIOT".
EDIT: holy crap i wrote a freaking essay O_o
I caught the palette thing, a couple people told me about the jumps. The one in my files has 3 or 4 more levels in it.
No comment.
) I really do enjoy the insight, and will keep it in mind. 
