Would give the game a 7 based off the demo, but i heard the game really starts to fall apart in the second half. So i can't really say until I play the full game, and I won't be buying this game new. I like this game better then colors. I didn't like all the blocky platforming in Colors. It's hard to compare it with generations because they are both really different and i like them both in their own ways. I would say that Sonic Generations is easily the better game though thanks to the classic Sonic gameplay.
Random thoughts i had:
Feels really slow at first but got used to it after a while
Performance is very rarely a constant 60 FPS lots of minor slowdown and pop-in issues, breaks the feeling of immersion
Game takes getting used to, which is fine for some games, but Sonic games have always been about being easy to get into and rewarding to master. This game shouldn't punish you for not knowing it well, especially on the first level. People should be able to have fun regardless of not knowing the game mechanics well.
Controls are need tweaking, very twitchy feeling at times, and can easily cause you to die for reasons that aren't your fault.
There is nothing classic Sonic about this game aside from the visuals. Very much so heavily Mario inspired, and that's a bad thing, all the good things about this game are the things that aren't taken from Mario.
The alternate paths are fun and the sense of exploration can be fun too
Speed running feels satisfying when you've found a good path
waaaaay too many automated sections, many more then Sonic Generations ever had.
the cloud sections are horrible
i like the random fast bits between all the slower paced stuff, keeps things interesting. would get boring if there was no fast sections.
Final Thoughts:
Sonic Lost World isn't a bad game, but it's not a great game either. There is lots of issues that need fixing.
Speed Sonic up a bit, get rid of all the Mario influences(timer, font, some of the music, the horrible uninspired boss battles, the uninspired level themes, the planetoids, crappy world map, etc), make the stages a big open world with lots of different paths to take with an emphasis on building momentum, put on next generation consoles so the game can run a constant 60 FPS without choking, put a bit more detail into the graphics, bring back stage ranks and give a reason for people to want to find alternate paths to get a higher score.
Also, give Sonic some good physics that don't feel like a faster version of Mario and get rid of automated sections that are just littered through out the whole game, and tweak the controls to not be so weird and twitchy. Also make the game mechanics fun for newbies but also something for hardcore Sonic players to master.
I think that if those kinds of changes are implemented in the next Sonic game then we will have something good on our hands.
I appreciate Sonic Lost World for trying something different, but it's copied Mario way too much for my liking. I love Sonic Unleashed/Generations and their boost, but honestly, I'm tired of boosting, as fun as it was. I would like to see SEGA / Sonic Team greatly improve upon what they've got with Sonic Lost World for upcoming games.