I'm enjoying it quite a bit, but I can see why the opinions are so mixed. There was one point in particular where, for some reason, I was focused on completing a segment a certain way and had to retry like 3 or 4 times. However, after that point, I just shook it off and decided to complete the scenario by reaction rather than planning. It seems like, if you become obsessed with a certain path, you may hit a wall and become frustrated. The game encourages you to react to what's happening on screen in most cases. I mean, there are often obvious paths that you become limited to, but those parts certainly wouldn't frustrate. When the level is opened up a bit, however, you're often given more choice than you may initially believe and you really need to approach the game differently.
I do feel that the game may actually be more enjoyable during a second playthrough, however. I spent quite a bit of time playing the demo, for instance, and I found that the first run through was actually one of the least enjoyable and that further refining my playthrough increased the fun just like an old school platformer. The first run through a 2D Sonic level, for instance, was rarely as enjoyable as subsequent runs would be. It also seems to me that the core mechanics are far more nuanced than you might first believe and the game can change drastically as you learn what you are actually capable of.
I know there is also a lot of hate for the 2D story sequences, but I really don't find them to be that bad. In fact, they really do remind me of the cutscenes used in the original Flashback or Another World/Out of this World. They also serve to hide loading.
