Well, from a certain viewpoint Sonic Boom's Wii U version really does look like a western, co-op take on Sonic Unleashed. Short speed levels with some platforming that tries to be 'what Sonic is known for', but the majority of the game is composed of more standard beat-em-up action with some traditional platforming strewn about. Rings serve as a health bar in a series-abnormal way, and enemies just circle you with the occasional attack. The lasso beam also can do what the Werehog's stretchy arms can do to a degree. All it's missing are the QTEs.
But yeah, it looks choppy, sluggish, and without substance. Plus for the Wii U and Cryengine 3, it looks worse than Unleashed, which is a six-year-old game by this point.
The 3DS version definitely looks better. I mean, the rival races would probably be a pain in the ass for players without high reflexes if it's as close a race as it was in the demos shown, and the tunnel level looked boring as hell. But the one main level certainly looked like good ol' Sonic with some unique approaches, and I sure as hell don't mind swapping characters on the go since, at their base abilities, they don't wildly deviate from Sonic himself - something Sonic Team's missed the point of for over a decade.
I really don't mind Sonic Boom as a spinoff continuity doing its own thing, but the Wii U game so far looks like the walking definition of a lazy tie-in game. And that's not even going into the in-game cutscenes that have Sonic Adventure 1-tier animations, compared to the normal cutscenes that look leagues better.