Man, I went back and tried to wrap up the final stars in the game (I'm at 110 right now), and for the life of me I just can't get past that damn Thwomp Stage in the Special World. I don't remember having any issue with this stage in the first Galaxy, but with everything running at double speed I just can't prevent either getting squashed by Thwomps (yes, I try to use the time-slowing buttons, but they're hard to get to and have to be timed exactly right) or falling off a ledge into the Black Hole. Honestly, I think part of the problem is that the camera for that stage is atrocious. If Nintendo had replaced it with an overhead camera, it would probably be a lot easier. I'm having similar problems with the comet on the stage previous to it, where they speed-up the rotating blocks. I didn't have too much trouble with that stage on my original run, but at double speed I'm finding that Mario just doesn't move fast enough to get on and off the blocks before they become too steep to stand on (oh, and the spin jump only seems to work on that stage when it wants to). It's just very frustrating.
I'm also running into a very weird issue with this game and the Wii in general lately. I'm in a new house, but I'm using the same setup as before. Now, however, the pointer's starting to get screwy. It'll be pointing at an object or menu item, and the pointer will just start jumping around the place. I'll recalibrate the sensitivity and that will work for a while, but then it starts getting weird again. I have no idea why it's doing that.