Aight, I can't believe I never posted in this before.
First of all, I thought this game was amazing. The level layout was amazing, the graphics were really good, and a the multiplayer was well executed. Although I do disagree with the save feature (having to beat a castle to save), it is call New! Super Mario BROS. Wii, and even in Super Mario World you had to do that. That being said, it is based upon the Bros. games, not World or 64, or Galaxy, so they tried to make the experience very similar, thus the save feature being the way it is, Yoshi leaving, etc.
So the game did have it's downfalls, but overall I think it was an expertly executed game.