I thought I made a "starter" thread on this but I guess that just shows how busy I've been lately, not that I have a ton of time now either, but I figured I should talk about Sonic Generations a lil since it's amazingly really good, and not just for a Sonic game, just good in general.
The basic story is Sonic Adventure and beyond styled "Modern Sonic" gets pulled through time to meet up with "Classic Sonic" and...well that's pretty much it. There's very little story or anything, just enough to hold it together basically, which is great and how how it should be. Though there are a few lil jokes here and there with newer characters meeting old Sonic and such.
The Good: Playing as both classic (2D) and modern Sonic (3D with some 2D also) through each stage. Even though you're playing through the same stage twice, it's obviously very different in play style and design. Though I thought I'd like the classic stages more, I think I enjoyed the modern style ones more, even though I like Sonic 1-3/Knuckles more than Adventure 1 and 2.
The Bad: Chellenge stages...these are unlocked after playing through the stages in an area before you go to do the boss battle. You're required to do at least 4 of them (3 to get keys to unlock the boss door and 1 for the chaos emerald of that area) but there are a ton of these damn things. Some are quicker/easier than others, some are annoying and unwelcome. Overall, they're really not all THAT bad...but in an otherwise great game these take away from all the other good stuff in the game. Not to mention, the time needed to make all these could've been spent making more of those well designed stages or more boss fights =P
The Awesome: I'll preface this by saying the last boss fight is super dumb and annoying. It's one of those modern Sonic stye gimmicks where you got the chaos emeralds just for this fight, oh well. This annoyance was taken away though by one of the best credit rolls ever as it showed each of the stages from their respective games with their original music, then the music transitions into the new remixes, super awesome. Then to top it all off, afterwards I'm informed that Super Sonic has been unlocked and you can then go back into each stage as EITHER Sonic and transform into Super Sonic once you hit 50+ rings and blow through stuff, crazy awesome. As a note, classic Super Sonic loses rings at normal speed while modern blows through them like crazy o.O To maybe offset this slightly, modern Super Sonic flies a bit off the ground and and easily go over tons of obstacles easily.
I'd say the game is easily worth it as I found myself playing through many stages many multiple times. The game gets more fun as you get better at it too as you rush through seeing shortcuts and alternate paths along the way urging you to try again till you find that perfect path to beat your best records. I just hope they add in some extra stages as DLC or somethin at some point, I want more =P