You'll have to report back. I'm interested if the game is really mediocre, or just doesn't meet the expectations people have of how sonic games play in their head. A lot of reviews I've seen compare it to an incorrect and nostalgic view of Sonic games. There seems to be a perception that you should just automatically breeze through a level. The original Sonic game stopped being the speed game by the second zone. That point on, speed was not the mechanic to complete a level. Speed became the reward for knowing the level. From what I've seen of gameplay, speed is definitely the reward and not the mechanic in Lost World.
Well I only played through the first 2 worlds so far (the Windy Hill Zone and the Desert Zone). I can't give you a full review or anything, but I can tell you that I really like it so far.
The gameplay is fast (not as much as Generations, but the level design isn't fully about speed like Generations was), but it's not easy. Unless you're really good, you'll have to slow down (so kinda like how you were explaining the original game), or you can very easily die. The game clearly has lots of paths through each level, some really obvious, some a bit hidden (some I couldn't find through multiple plays through some levels), and some containing different things (some hide red rings, others have challenges for extra lives). There's a lot of exploration, but a lot of the areas have segments that really require skill to get through.
The gameplay is very different from previous Sonic games (and, despite the stupidity of many reviewers, is nothing at all like Mario Galaxy), but it does feel a lot like what you'd expect from a good Sonic game. The controls are really odd at first but playing a couple levels will get you used to it (the "hold a button to run" thing feels odd). Not a fan of the wisps though, but I hated Colors, and the Wisps were the only thing I didn't like in Generatons, so this is no surprise.
So far I'd say the negative reviews come from reviewers who didn't want to adapt to this new gameplay style, and instead decided to bash it for stupid reasons instead of giving a proper review (which makes sense considering "professional" game reviewers have long been notoriously bad at games). This seems to be like all those stupid W101 reviews where the reviewers didn't want to learn how to play so they gave up after a level or 2 and gave it a bad score for illegitimate reasons (and the video portions of these reviews kinda prove that, clearly they were unable to play the game at all).
