Flo Lieb’s review published on Letterboxd :
So, this movie was originally announced to be released the same year as the Disney version by Mr. Favreau. But then they held it back, saying they wanted to work on the VFX. This is never a good sign.
Years go by, finally the movie is due to be released. But then it isn't. Instead it is bought by Netflix to be released as one of their "original films". This is never a good sign.
Despite the years-long delay and the buy via Netflix you would not expect Mowgli to be as awful as it is. But it is.
Considering they originally delayed the release to work on the VFX the final CGI is so god-awful I can't even imagine what it looked like when the movie was initially supposed to be released in cinemas. These are the ugliest CGI animals I have ever seen. Baloo looks like some inbred hillbilly version of himself. Essentially all of the animals, from Baloo and Bagheera to Shere Khan, have utterly fucked up eyes. So large, like you crossbred Sailor Moon with some forest critters.
The proportions are totally off, too. The wolves are of natural size. Hell, even the tiger if you ask me. But Baloo is a sloth bear and comes off as if he's a grizzly. Why is he hanging around the wolves all the time anyway? And Kaa is so huge she might be the Midgard serpent, trying to wrestle Thor during Ragnarok.
Similar to Favreau's version it is unclear why some animals can speak and others like the monkeys, elephants and prey can't. I get why the prey doesn't speak, just as in The Lion King it would be morally and tonally off. But ultimately there is no reason why the elephants are silent yet the python talks.
There is a 10 minute portion where Mowgli joins the human village that is actually decent. Both filmed and narratively. Like the ending it makes one wonder why Serkis didn't chose to tell his version of the story that way from the beginning: either Mowgli's adaptation into human society or a grown-up Mowgli's fight for the jungle. The finished result is neither here nor there, wasting on-screen actors like Freida Printo and voice-actors like Christian Bale and Benedict Cumberbatch. Why use the latter ones when you distort their voices so much they hardly sound like themselves anyway?
It probably is meant as a homage to The Lord of the Rings but why have Mrs. Blanchett open the movie with a monologue voice-over? It doesn't even really make sense regarding the Kaa-Mowgli relationship. If anything, have Mr. Bale do it since Bagheera is closer emotionally and narratively to the story and the character (I don't really understand Kaa's investment anyway). There are other shots that further show that Mr. Serkis might not be a very talented director.
Ultimately, being picked up by Netflix might be the best thing that could've happened to this movie. Since it is so terribly bad, they would've destroyed it during its cinematic run. As shitty as it is (similar to Annihilation, Mudbound et al.) it fits perfectly in Netflix' "original" archive. It might very well be the worst film of 2018 regardless.