Okay, so, I beat the Wii U version late last night. I think the game as a whole is an interesting experiment. If taken as a proof of concept, it actually accomplishes that goal pretty admirably. However, it feels like a rough draft that could benefit from more focus, elaboration, and polish.
What Lost World does best is really define Sonic's controls. I'm not 100% satisfied with them (his mid-air arsenal leaves room for improvement, IMO), but they're strong enough that most players will be content. I miss mid-air boosting. I am confused why we cannot use the ground stomp in rail sections unless it's after a homing attack. I think his wall-running is also pretty finicky. Wisps in the game are generally awful and underutilized, too. Other than what I've mentioned and a few other little things here and there, Sonic's movement is Lost World's strongest asset.
Most stages in the game are a different story, though. Level designs are all over the place, with the latter half of them devolving into unwanted gimmickry or punishing linearity. The game's lives system is also pretty frustrating when coupled with spotty targeting and a few iffy checkpoints. If everything felt 100% my fault, I wouldn't have minded as much, but some stages drag forever and have some freaking obnoxious things in them...
I just feel like I'm not on the same page as Sonic Team with this one, especially after playing the first level of that Special Stage or whatever with the Rubik's cube block stuff. I have no clue what the hell that nonsense is.
The soundtrack is nice but nothing too special outside of a few songs, and I thought the presentation of the story is a little better than Generations, at least.
Our tastes are similar regarding those other Sonic games. Personally, I felt disappointed with Lost World in comparison. Its still fun when it's not being annoying, but it doesn't grab me as much as the Boost trilogy, even at its best. It's kind of its own thing. =