I can't exactly put my finger on what it was, but it just didn't capture me like I thought it would.
I played 4 or 5 levels. Once I got through one, I really had no desire to go back and try to collect all of the extra stuff unlike with NSMBWii or SMG where I have played levels over and over and over until I got everything.
After a very brief period of time, I moved on to another game and never picked it back up until I sold it.
Now Playing: Pikmin, Super Mario Galaxy 2