I did the first 2-3 worlds all golds/platinums on easy and was enjoying the game more. Easy mode was pretty fun because you can make large movements and go fast to get the best times. In fact, I got so used to going fast and controlling the starting marble, when I got the Rugby ball I just stuck with the starting marble. Then world 4 had some level with a really stupid canon part that took me 50 tries and 10 mins of JUMP IN CANNON AND FLY THE WRONG WAY. When you have to land on little platforms with not much leeway the cannons really ruin the game for me. They are so sensitive and I can't hold the remote 100% perfectly in the direction I should be.
Then I finished up world 4 and before going to world 5 it said I had to get parts. I did the city extra stages, which were ok. But then I got to the candy extra stages and it was just annoying so I turned it off and am shelving the game permanently. The weird sideways/upside-down whole 3d movement just feels unintuitive and I can never move in a STRAIGHT LINE horizontally or vertically when the control is sideways or upsidedown. Between the 3d movement and the cannons it's just not fun for me anymore.
If I had one wish granted for the marble rolling genre, it would be an option to use the nunchuck analogue in all future rolling games. I get that people like the "tilt" idea because it's more like those real life marble rolling puzzles, but it's just less accurate than an analogue and makes the games harder and more luck/wacky physics based than the olden marble rolling games. I mean Monkey Ball on GC analogue controlled PERFECT, yet they bring MB to Wii and add tilt and it controls horribly and the game sucks. Then they bring Monkey Ball to the iphone with tilt and the game controls horribly and sucks. If you want to keep making tilt rolling games, then fine but give an option to just use a damn analogue for those who don't enjoy tilt.
All my favorite Wii games are 90%+ analogue based. I have a lot of dislike for tilt, pointer, or gesture based titles because of control problems in many of them.