Coming from an ONM review...

Score: 92/100

(+) A turnaround of ideas to rival Mario Galaxy
(+) Asymmetric Multiplayer finally done rights
(-) Not quite as good for the lone wolves

- multiplayer 'is more welcoming that New Super Mario Bros U's, mainly thanks to heroes being able to pass through each other and the absence of a life counter'
- sometimes the game's focus on multiplayer is at the expense of single player
- praise for the difficulty level
- 'core' levels are relatively easy (which will last around 7 hours apparently
- optional stages and 'invaded' have brutal difficulty
- on the controls 'this is what the Gamepad is for'
- great replay value