This game is great. It really should have been a 3ds launch title. It makes awesome use of the 3d, it has great picture quality, and it combines the linear style of New Super Mario Bros. with the gameplay of Super Mario Galaxy.
It is way too easy. Worlds 1-7 are a breeze. You start each level with a power-up, and if your having too much trouble with a certain level, it gives you a tanooki leaf that makes you invincible throughout the level. and there is a semi-glitch (watch Egoraptor on youtube) that gives you hundreds of extra lives. World 8 is a monster. They give you seven easy worlds, then throw you into the hardest mario world in video game history with next to no preparation. The first seven are definitely aimed towards little kids. Another thing that bugs me is the storyline. They didn't even try. They have one scene in the beginning that shows tanooki leaves being blown all throughout the kingdom, and then mario gets a picture of peach being kidnapped by bowser, and then off he freaking goes.
Overall, the game is very fun and entertaining. Other than the difficulty level, it's awesome.