Héctor G. López de Victoria’s review published on Letterboxd :
I wouldn't say Rio is a good movie, but it has its merits. I certainly enjoyed it thanks to steady pacing and satisfactory character growth, and I think the way they pay tribute to Río de Janeiro and its enviable culture is commendable. What I didn't like is the way the film fails to tie all these characters into believable, strong relationships. Also, all the musical numbers after the rather brilliant opening are difficult to digest... They feel much too current and hip, in a cheap kind of way, and don't say or do much towards advancing the story.
Oh, and whoever envisioned will.i.am as a "swagger"-spouting macho bird stereotype: find another craft.