I'm keeping this at arm's length because everything has been smashing my heart into pieces after Colours was a super high for me, so I don't know how they're approaching it, but the structure of this is probably the most important factor to me. I'd rather have anything but modern Sonic levels removed outright. Use those Colours design sensibilities to make multi-layered and replayable levels instead of trying to create padding with all these mandatory extra characters.
But if you NEED to put in a variation on treasure hunt or fishing or werewolfing or classic Sonic-ing just to hit that 10-15 hour span or whatever, pllllllease take a page from the gosh darn FIRST 3D Sonic game.
Sonic Adventure had the most extraneous garbage out of all of these games, but had the decency to chop it up and make engaging with it optional, and more importantly, gave you the power to choose when to engage with it.
Sonic Adventure 2 immediately made what I consider to STILL be the worst decision 3D Sonics ever made, which is forced all those jarring gameplay variations on you. A lot of people love SA2 and I genuinely do respect that, but to me it's probably one of the most miserable times I've had with these Sonic games, because it would not just let me play the game I wanted to play at a given time.
Even Sonic 06 with its smorgasbord of problems let you be like "eff this Silver guy for now, I'm just gonna play these Sonic bits". I finished Sonic 06 every way from sunday, eventually, because they didn't shove Silver bits in my face when I was in a Sonic state of mind. Which... a lot of the time involved breathing exercises when Havok physics randomly threw crap at me.
I think I would hold Unleashed in fairly high regard if I could just deal with the Werehog stuff when I was mentally prepared for it.
Because to be absolutely truthful, there are very few characters/gameplay types in *any* of the 3D Sonic games that I thought were so bad I couldn't even get through them. Down to fishing with Big - which was like this wonky, largely inoffensive version of fishing in most non-fishing games.
So it's not really so much that I hate playing as Classic Sonic in Gens, as much as it is about being jerked away from being in the modern Sonic groove - and vice versa.
Colours was a shining beacon of hope because it showed that Sega ABSOLUTELY know how to make one of these games content rich without having you leap between two wildly different speeds/modes of play, and that's why anything less than that feels like such a travesty to me now. But if they let me choose when to deal with these three, essentially different games they've shoved into a tortilla bread and called a coherent game, I'll deal somehow.
It's unfortunate that Gens showed that their multi-character approach makes them comfortable with simplifying the modern Sonic levels to merely encompass a number of set routes, but I've honestly come to terms with the notion that the Colours template is never coming back, anyway.