...and by 2D I mean side-scrolling as opposed to being able to move freely in a 3D space. We really need some better terms to describe this stuff with the newfound popularity of stereoscopic 3D games. :evil:
So yeah, I like 2D gameplay better than 3D gameplay. Most of the time, at least. I realized this recently after playing several games that feature both 2D and 3D formats, and I prefer the 2D gameplay in every case. Super Mario Galaxy 2, Other M, Mirror's Edge and Prince of Persia: The Forgotten Sands are the first ones to come to mind, and de Blob 2 also features new side-scrolling sections that look fun, but I haven't played it yet.
There isn't much to say about SMG2. It has side-scrolling sections and they're awesome. They allow for more deliberate design decisions, I think, since the player isn't distracted by trying to look around the environment or getting the camera to cooperate.
Other M is the only weird game in my list since it isn't exactly all 2D and it definitely isn't better than the 3D games overall. I still prefer its gameplay, though, because it at least has the POTENTIAL of being much better than a fully 3D Metroid game. The combat is definitely more fast-paced and easier to handle since you don't need to worry about aiming at everything, and the old 2D games proved that you can hide a lot of stuff in a 2D plane.
The original Mirror's Edge is a really fun but flawed game, but I got the iOS Mirror's Edge on my iPod recently and its gameplay is much more fun to me. It's a pure sidescroller, but it totally maintains the essence of the gameplay from the original. The goal is to keep running without slowing down while sliding under or jumping over obstacles, wall running, taking enemies down (which is less of a hassle in the iOS game), etc. Each level has some hidden bags, so I use the first runthrough to find the bags, then I go into the speed run mode and try to make a perfect run. It's a short game, but the concept is good enough to warrant something similar in the future... Maybe an XBLA sequel or something.
Prince of Persia: The Forgotten Sands (Wii version) surprised me with its 2D sections. I'm only a couple of hours into the game, so I don't know how prevalent they are, but I've hit one 2D section in the main game, and there are several unlockable challenge levels that all take place on a 2D plane. The 2D sections focus more on speed and precision rather than figuring out how to get from point A to point B, so while they use the same mechanics as the 3D parts, they feel different and offer different challenges.
I'm glad that 2D gameplay has made such a comeback in recent years. There's something about its simplicity that allows for a more concentrated brand of fun than most 3D experiences offer. Of course some games can only work in a 3D environment, but I love to see what devs can do by setting their games (or at least parts of their games) in a 2D space.