But that's just it, Colours was exactly the same but just focused less on speed and more on how you explored and interacted with the environment.
But Sonic Colors was plodding! It had poor, awkward controls for the type of platforming it wanted you to do. Like a lot of modern Sonic games, it had "momentum" in its air control, which is secret code for "you never land on the platform you are aiming for". It was especially bad in Colors, too - a lot heavier than Unleashed or Generations, I'd say. And you do a lot of stupid jumping puzzle bullshit in Sonic Colors - more than almost any other Sonic game
ever made. It might actually be a contender for one of the slowest Sonic games, outside of obvious stuff like Sonic 3D Blast.
It seems that games like Unleashed are good if you want to mindlessly blast through levels without really drinking them in, which kind of negates the point of making them look attractive if you are too busy dashing past them to notice, while Colours had little touches like the lower area in one of the Sweet Mountain levels where you can use switches to interact with enemies in the distance and skill is required to hold onto all of your rings and get a good score.
If you really think Sonic Unleashed is about "mindlessly blasting through levels without drinking them in" I don't think you were really playing the game right, or weren't paying attention to it in the right way.
Plus, I mean, let's talk about all of the rich detail you get in Sonic Colors when you're forced to slow down. The bit in Sweet Mountain doesn't really count, because that doesn't use anything unique to Sweet Mountain's environment type - you are not crushing robots with cheeseburgers. That could've been in Starlight Carnival, or Tropical Resort, or anything, because it's just buttons and spike pits - it's entirely divorced from the level theme.
It doesn't matter if you're going slow in Sonic Colors, because it is not as though you are "drinking in" the environment anymore than you would if you were running fast, because Sonic Colors, like Sonic Unleashed and Generations, is more or less built on the idea of "tilesets" - which is to say there is nothing to distinguish Pagoda #1 from Pagoda #4731 in Aquarium Park.
Nor are you really traveling too fast in Sonic Unleashed to not notice setpieces like the giant clock in Rooftop Run, the eagles in Dragon Road (or, indeed,
the dragon roads), the cars in Skyscraper Scamper... I could keep going.
And that's completely ignoring the fact that a lot of levels in Sonic Unleashed actually have details and areas that are only really noticeable if you slow down and look for them. There's a whole cafe area complete with readable menus and a moon medal in Windmill Isle that is almost impossible to see if you're running at full speed. There are a lot of cases in Unleashed where it pays to slow down and creep through the level at least once, and things are set up so you can do that if you want.
Also, I don't know if this is a difference in how the Wii handled effects compared to HD systems, but I found it much easier to admire the environments while playing in Colours than I do in Generations. Some parts of the latter are a literal blur to the point where I don't even feel like I'm even controlling Sonic (and often run into things I didn't really see coming). The Wii's boost effect, for instance, is very stripped down in comparison and the game benefits from this.
It sounds to me like you're faulting the game for something you yourself are having trouble handling.
As for the quote on "Mario-izing Sonic"... here's
an IGN interview:
"From a general game design perspective, in recent years we've been able to introduce Sonic to new fans, a lot of the Nintendo/Mario fans, and because of that, we've made changes to the design, and we've designed things in Sonic Colours that we think will really appeal to people who are unfamiliar with the Sonic brand and the Sonic gameplay. So from that perspective we hope that fans of Mario will really be able to enjoy playing as Sonic in Sonic Colours."