Christopher Bird’s review published on Letterboxd :
What it mostly is is "okay." This is basically the sort of movie that would exist in the ZOOTOPIA universe - it's a fun trifle of a "let's put on a show" movie, but it doesn't have the remarkable depth and intelligence of ZOOTOPIA, nor does it have that film's stunning visual invention for the most part (one clever moment with glowing squids aside). It's just a regular world with talking funny animals in it.
Most of the performances are great. The exception, of course: Seth McFarlane's stupid fucking Sinatra wannabe mouse is predictably awful, of course, because it's just another excuse for an asshole Seth McFarlane character and for Seth McFarlane to indulge in his penchant for lounge singing.
But Reese Witherspoon is lovely as the lady pig, and Scarlett Johannson is fun as the porcupine, and Taren Egerton is terrific as the gorilla, and the fact that I'm not using the characters' names because I can't remember them now is probably pretty telling about how deep the story is here. But they're all remarkably good singers, and that's fun. Matthew McConaughey is sorta coked up-sounding as the scammy koala for a lot of it but at least he's enthusiastic, and I can remember his name (Buster Moon) because he's one of maybe two characters who has a *last* name. It's so weird when he's introducing the various singers at the Big Show at the end by their first names only, but then again I already said: this movie isn't deep.
It's a slight trifle and won't be remembered for much of anything beyond the already-greenlit sequel, I suppose. But it's not bad.