How does Amy feel in terms of controls?
Using aspects of Amy's gameplay from Sonic Adventure/Sonic Advance is always a win in my book. I do have my gripes with her (detailed below) but overall I'd say she's my second favorite character for casual playing, next to Sonic.
What are your most and least favorite aspects about her playstyle?
"Timed hit"-type mechanics are awesome and I wish they were present in more games. It's the reason why the Insta-Shield is my favorite Sonic ability and why I enjoy
(some of) the Mario RPG games so much. Before writing this post, I went and played the whole game as Amy, but this time going through areas I don't commonly visit or doing things I don't usually do, like chasing down Fang instead of waiting until he stops bouncing. Made me like her twinspin much more, it can be very tough but also very fair. I like that if you hold down the jump or spin button as you hit the ground while doing the twinspin, you'll get an instantaneous melee attack on the ground, as a little extra safety in case you missed by just a thread, a la deathbombing in Touhou. The little things! And I imagine the ability of doing the twinspin in the air by pressing spin instead of jump was done because of how natural it feels, and it's right!
...Though that is where the problems start. Having that option, and coupled with how
natural it is to do, trains the player into using twinspin with the spin button, which
will lead to disasterous results with a shield on, and then you have to counter-train yourself to stop doing that. Speaking of natural, it also feels natural to be able to twinspin after using a spring - but you can't do that. Not even if you twinspin off of said spring, even after you know that you can keep twinspinning after hitting an enemy or monitor (which is something I'll get to shortly) and twinspinning into a spring has an actual effect that seems to be there to help you continue your chain. It's a conveyance problem - jumping and springing have the same animation and similar mechanics (neither of them allows you to touch an enemy and live, unlike S/T/K/M who damage enemies with a jump but not off a spring and have different animations for each) so it makes one think twinspin is possible with both. If I could sprite to save my life, what I would do is make Amy have her hammer out whenever she can do her twinspin and make her hammer go away when she can't. This would also solve something I mentioned earlier - if you successfully hit an enemy or monitor with a twinspin, you can twinspin again. Which is indicated absolutely nowhere, I found out about it by complete accident. Lastly, I've barely touched on the ground melee attack. It's... meh. I use it mostly if I
have to, otherwise I stick with midair twinspins. Maybe its recovery time does need to be reduced slightly, as in
Katmint's Revised character and shield abilities script.
Also something something steep slopes, something something her spring boosting is not really utilized by the levels, something something ground friction ruins horizontal springs for her. Those things have been covered elsewhere in the thread and by people who could explain them better than me. Also yes a bunch of what I said in the previous paragraph is stuff I'd say about Fang as well.
If there is anything that you felt Amy is "missing", what sort of gameplay changes would you be most interested in seeing?
Regardless of what I said in the last section, being able to twinspin after a spring is something she
needs, at the very least if the spring is one she twinspun or melee'd onto. She should also gain a wee bit extra height from each enemy/monitor bounce she does. These would put a lot more focus on her ability and makes her stand out from the others that much more. Also, this would break the heck outta people's replays so I don't expect it to happen, at least not until 2.3, but I wish Amy was unable to use twinspin with the spin button. Jump abilities should only be performed by pressing the jump button in midair, as is the case with every other character.