We could be discussing ways that super forms could be feasible and not detrimental in vanilla because there are (I think the stance that says super forms are irredeemable as a mechanic is as hardline as the super form purists' and should go) and even more so now that it's a real possibility if well conceived.
Honestly there's already been a lot of discussion in this regard a while back in this thread, but I will go ahead and reiterate some of my ideas in this regard all in one place in this post, since it seems like an opportune time to do so. Some of these ideas will also be new.
Sonic: His hover works more like Metal's current hover where he drops slowly with low speed rather than just falling. When paired with Tails, Tails will also transform when going Super.
Tails: For his super form, I feel like what would flow well with his playstyle is for him to retain speed while flying and to be able to do so for longer (But still not infinite). His swimming ability could become infinite however, and he could gain the ability to carry other characters on his back while swimming. I would pair this up with either a traditional ring drain, or make it so he gains some sort of extra ability that costs rings while transformed.
Knuckles: I would speed up his gliding and climbing while transformed, give him the multiglide (Perhaps have each glide after the first one but before landing have a ring cost of a certain amount), and when he attaches to a wall it causes a shake that destroys nearby badniks from the sheer force of him colliding with the wall. He also gains the ability to swim along the surface of a body of water.
Amy: She doesn't become invincible, but loses 15-20 rings when taking a hit. Her hammer range is increased, she does two hits worth of damage every time she hits with her hammer, and holding spin while jumping allows her to do a hammer smash that gains a little bit of height and forward momentum while spinning with her hammer before she comes down and smashes the ground, hitting all badniks within a certain range of her, perhaps the closest ones being hit by a circle of hearts that spawns around her and those further away taking less damage. She could also potentially launch herself even further than base form when hitting a spring with her hammer.
Metal: His base form is tweaked so that his V. Maximum Overdrive gives him a temporary speed debuff down to walking speed when he finishes using it, complete with a sparking effect to indicate the damage he has done to himself in the process. His base form hover also works the same as current Super Sonic's in that if he moves too slow, he drops like a rock. Pressing spin in the air allows him to charge up the V. Maximum Overdrive, with him falling slowly in the process, effectively it would be like a spindash in the air but without actually spinning. Releasing it before it's done charging would just give him a little speed and not the invincibility that comes with it. Charging it while moving would kill all speed, even while going fast. This could be done multiples times, but each time charging it would result in losing a bit more height.
After going Super, he gains the better hover that can only fall slowly, and he can use the V. Maximum Overdrive without worry of getting any kind of debuff in the process.
Fang: He gets on his bike. While on the bike, he cannot lose rings and gains a considerable boost to speed and jump height. However, the bike can only take a certain number of hits before it despawns. This could either be a strict number, or a health bar that could potentially be recharged with rings (Think of the mechs in SA2). The bike actually spends the 50 rings used to summon it, leaving the player with 0 if they only had 50 rings when they did so. This would not despawn the bike, but could result in the loss of points at the end of the level.
