If you mean the "S" shapped tunnels, she does curl in them in Sonic Advance. Anyway, thinking over what E-122 said, the reason why Amy's abilities would be hard to implement is something that happens if the original game code does not accomodate certain actions /attributes from the start. However, a code that were to be built from the beginning to do so like it was the case of Sonic Advance would not result in such issues such as figuring out how to make a specific move work because the resources would already be there. In this case, a sequel would definitively be the best place to feature Amy rather than add her as an afterthought. Still, not changing my opinion regarding Mighty/Ray because if they do turn out to be Sonic clones, this would be a situation of quantity over quality. However, if they do turn out to be something more unique, then that would give rise to the question of why this effort was not given to a character with more presence in the franchise? I could argue that Amy's advance gameplay has it's positive qualities, such as: * A unique gameplay that not only features abilities exclusive to her, but also something that neither Tails or Knuckles offer: balance. Where those two do everything Sonic does plus more, effectively reducing the protagonist character, with Amy you have an actual balance where one character's weaknesess are the other's strengths and viceversa. * The lack of roll doesn't hurt the gameplay, since rolling was never an absolute need to build speed. All character can achieve this by jumping at the right moment off of slopes and other curved surfaces. For example, jumping off the middle of a loop is a better alternative to rolling, and unlike rolling, it is a more involved action with a risk/reward factor to it. * Offers a more substantial alternative for those players willing to test their abilities with a more technical approach, something that I do not find in a cast that consist of two additional characters who are derived off the protagonist's moveset, on top of how they ultimately end up feeling samey. Personally, I think that when playing as Amy, the result will reflect the skill of the player as well as how well they understand the mechanics of the Genesis games. If the challenge is too much, one can always go back to the more safe options that essentially play the same. Lastly, the argument of this not being a fighting game doesn't hold because platformers come in different styles. You have those where landing over your enemies is all you need, others where you have to manually attack, others where you shoot, etc. Sometimes breaking out can result in a new challenge that in instances, can be just as much, if not more enjoyable than the original style. I like for example playing as a sword wielding character in a Contra game (Sayuri from Hardcorps Uprising), and a similar thing I can say about Amy, since the character still plays by the same rules, but adds some twists to them. If you don't like it then that's your opinion just like how I have mine and can develop on why I think it's an addition that sadly got overlooked for a criminally long amount of time.