I have watched it yesterday too ...

Hmmm ... lots of mixed comments,
there are some things which I like, 
and there are some that I thought are rather "typical" of Japanese comedy ...

What I like ...

-- definitely the dance moves ... well, to many of us, they could probably even pass off as Hawaiin dancers ... 

-- not many talked abt her, but i would like to commend on the actress who acted as the mother ... hmmm ... a particular scene stood out ... the scene whereby she went to the dance school to deliver the parcel, and simply stood that, with "mixed" emotions ... not much expressions, but she could probably exude to the audience her full of mixed feelings ... * clap * ... and following that, her pulling of the cart, and her delivery of lines abt what she used to think ... simple supporting role, but very convincing ...

-- rather subtle in some of the scenes (abt feelings/thoughts) etc ... and a bit "philosophical" near the end ... 

-- inspired by real events, i thought the last 1 hour was pretty good ... now you ask, why dont i say so much abt the beginning?!

What I thought could be better?

-- Hmmm, the front portion was okay to me (not great, but not too bad either) ... why?! ... i thought it took on the stereotypes of many typical Japanese comedies ... with some rather exaggerated expressions (forgive me), with some predictable "roles" (abt the various dancers), and to some extent, a bit similar to those "underdog" stories ...

-- in contrast to some paras above, some scenes are not too subtle, and rather obvious/exaggerated/predictable ...

Conclusion:
Recommended ... but frankly, I prefer the second half to the first half ... is it really the Best Film from Japan last year, let me watched a few more and tell you ...