I'm warming up to the game. I love the new detail they gave the backgrounds, and the level design seems more interesting.
Boost Mode seems like a fun way to get casual gamers to participate. It is kind of cheating though, since you could use the assist blocks like a bridge, extending them over all the traps on the ground.
I am extremely disappointed that there is no level editor in either the 3DS or Wii U versions of NSMB. The touch screens of the 3DS and Wii U would make creating your own levels a breeze. Nintendo has a huge opportunity to go after the LittleBigPlanet players, yet they fumbled it again.
I am also confused by the naming of the NSMB games. It should be like this:
NSMB (DS) = NSMB 1
NSMB Wii = NSMB 2
NSMB 2 (3DS) = NSMB 3
NSMB U (Wii U) = NSMB 4
The games should be numbered in the order they were released. The 3DS version is the 3rd NSMB game, so it should be called "New Super Mario Bros. 3". Or maybe Nintendo considers the handheld and console NSMB games to be separate from each other.