CaptainGyro: I heard a bunch of times that it was better than the first, what's wrong with it?
RayRay13000: I liked it as much as the first one from the times I got to play it (although I don't own it). It's really just the same thing as Super Mario Galaxy 2 but with different levels and Yoshi. The story is pretty much the same with Peach getting kidnapped and Mario off to save the day...again.
While SMG brought a lot of new game play to the table SMG2 did nothing of the sort, in addition just tacking on some levels that could be easily confused with the levels in the first one.
gameon: I dont know, because when i heard it included a screen on the controller, i didn't think it had ever been done on a home controller (unless you count the dreamcast). I also heard rumours you could use the controller screen as the main screen (without needing a tv) Whether that's true or not i don't know. But it is a selling point.
You can, but try and imagine playing a 1080p picture on a 5 inch screen, it's unpleasant at best. Everything is too bloody small to interact with, etc. Yes, if you get kicked off your WiiU's TV you can simply switch to screen only play, but as a selling point I see that as rather niche.