With Frontiers' final update finally giving us a playable supporting cast in a 3D space for the first time in over fifteen years... how do they stack up compared to the past, and what can other characters learn from if they ever returned?

As for my opinion, for every character who's had more than one playable appearance in a 3D game, it'd be something like...

• Sonic: Frontiers. Adventure is very close but Frontiers has more versatility and customizable options that are so thorough, an optimal Sonic in that game just feels like a second skin. It's uncanny how seamless he's felt with the right adjustments and the latest DLC really push those limits in the best way... at least in terms of platforming.
• Tails: Frontiers. Flight is top-notch in my opinion, really gives you room to control yourself in the air and the wrenches are a neat bonus on top of that. I'd say it's a very balanced approach to Tails that isn't too broken if it weren't for the Cyclone, but that's so fun I don't even care.
• Knuckles: Adventure 2. Gliding controls like a dream, and the rest of his kit complements his stage design beautifully. Combat could be better, but the Adventure games didn't really care for that so it was never distracting. Frontiers leaves a lot to be desired; combat's subpar, climbing's limited, and gliding is like steering a boat. Not fun.
• Amy: Frontiers. More hammer abilities would be nice but what's there is still a wonderfully-acrobatic spellcaster-type character who despite feeling noticeably different, still has enough familiar techniques to feel like she's from the same game as Sonic.
• Shadow: Adventure 2. I like his unique attributes in Shadow, '06 and Forces, and some abilities like the Light Speed Dash and Homing Attack have improved over time... but in terms of physics and movement controls, yeah, the Adventure games are still king in that respect, but Frontiers controls with some Chaos powers or other unique skills could top it.
• Rouge: Adventure 2. See Knuckles, basically.
• Omega: Heroes. Even without '06 being the clearly worse one of the pair, his Heroes combat is just the stuff of dreams for a character designed around raw power. The sheer destruction Omega is capable of in that game is just nuts. Project '06 knew this and worked with Heroes as a base first and foremost.
• Big: Heroes. See Omega, but substitute Sonic '06 for fishing. His size and fishing rod complement combat wonderfully and his parasol is a cute little detail that works great for a big guy like him to move around efficiently. If you haven't played Big's Big World, for the record, that is peak Big control for these exact reasons.
• Blaze: '06. Frankly even in a game that does its cast no favors in gameplay... ever, Blaze still ends up being fun in her own right, with a kit that has its own flair without being too far-removed from what makes Sonic fun, even compared to Sonic himself in this case. Plus... well, Black Knight's kind of a simple game and it'd be a travesty if that were her best playable appearance. It was close enough for both her and Knuckles and that's a scary thought.
• Eggman: Adventure 2. The fact that I forgot Sonic R existed should already be enough of an indicator of why SA2's on top, but even past that... shooting stuff is great, and with stages like Cosmic Wall that allow you to move around freely in the air, it's especially exhilarating. Gamma's better but hey, this gameplay style still has merit as long as it's never as heavy as a rock again.
• Metal Sonic: Adventure DX. Oh right, he was playable in Sonic R too. See Shadow for everything else I guess, although I prefer the floatier controls of SA1 compared to SA2.

And... there are also mobile games and Sonic Speed Simulator, but... correct me if I'm wrong, the latter doesn't have a lot of discrepancies in terms of how the characters all control, and the former doesn't really fit the definition of a platformer. Whatever.

So... yeah. Eleven characters, not even counting all the 3D one-offs like Team Chaotix, Silver or Cream. SEGA's got some catching up to do.