Heroes: No story whatsoever, and you had to play the same levels four times over to actually complete the game. ir easy even with Chaotix, who were supposed to be the hardest team to play as, (Or maybe it was Dark, but it was ir easy with them as well.) except for getting the chaos emeralds, which didn't really last that long and wasn't really that much of a challenge either.
Shadow: Very mediocre gameplay, horrible controls, especially for the vehicles, (though if you're an extreme hardcore expert, you could make it seem like the controls are at the level of "meh.") horrible story, (Gerald, a person smart enough to make the ARK and all kinds of crazy s with 1950's technology and infrastructure, couldn't figure out that Doom might have ill intentions?) and why the hell is everyone saying "damn" like children who've just learned the word?
Sonic '06: "WHY DEAR GOD WHY!?" was uttered by all but the most hardcore (read: retarded) fanboys and girls. The most stupid plot I've seen in a great while, (And I have seen some horrible, horrible plots.) controls worse than Shadow, and JESUS fg CHRIST ON A POGO STICK ON A UNICYCLE ON THE EGG CARRIER, SONIC AND ELISE? WHY DEAR GOD WHY MY EYES THE PAIN IT BURNS IT BURNS! SO MANY HORRIBLE FANFICTIONS, MAKE IT STOP! MAKE IT STOP! MAKE IT STOP! They didn't even do anything, anything at all, in the six months between the 360 release and the PS3 release besides changing the button instructions. (Or was it PS2? I can't remember, because it's utterly horrible and I blocked all things relating to it from my memory, but I'd think it was the PS3.) Well, at least this horror of bad gameplay, bad fiction, and HOLY f BESTIALITY was erased from existence. Thank Christ.
Secret Rings: Boring as all hell, poorly done cutscenes, (I can mildly understand a more book-like look, seeing as it's in an actual book, but it just looks so boring.) and why do I have to hold a button to stop Sonic?
Rush & Rush adventure: Original was mediocre, second was of even lesser quality, and the material system was just a way to pad the game by making you play through the same exact levels multiple times. The little Australian raccoon or whatever she was was the most annoying Sonic character of all time. Seriously, at least Cream is courteous. Also, they can't keep Blaze's backstory straight. That or they don't care. Either way it's a bad sign. At least they're being mildly different with their endgame plot twist, and by that I mean that instead of making some crappy new villain come practically out of nowhere with some crappy disjointed plot twist, they make Eggman (and his alt-reality/from the future/whatever counterpart, Eggman Nega) come practically out of nowhere with some crappy disjointed plot twist with Metal Gears--I mean, Transformers--I mean, Gundams--I mean, original large machines.
Unleashed & Black Knight: Holy s, games that are actually good? Not quite. They're a fair improvement over previous attempts, but they're still all around mediocre.
Really, watching Sega and Sonic team work together to make Sonic games at this point is like watching a horror movie: you're just sitting there, saying to yourself, "Oh, something good actually happened to the protagonists? I didn't expect that. Now, I wonder what horrible thing is going to happen to make their lives miserable and scar them forever, if they even survive it?"