I watch a lot of kids' movies, at least for an adult. If you're wondering why, that at least is easy: because I enjoy them. Some of them. They can be enjoyed because of a good story, beautiful artwork, or sometimes because the writers have put in jokes that target the adults in the audience. Pixar's movies often manage all three. This movie is rather less successful.
Here's the kids review first: it's colourful, fast-paced, and funny. They'll like it.
Here's the adult review.
The movie opens inauspiciously with blatant CG images of Pokémon roaming in the wilderness. The CG is ... good, but nevertheless very obvious and decidedly damaging to your desire to suspend disbelief. Our two main characters are Tim Goodman (played by Justice Smith, not a great actor although undoubtedly dealing with a great deal of green-screen-only acting) and a talking Pikachu. Voiced by Ryan Reynolds, channelling a kid-friendly version of Deadpool. I loved the first "Deadpool" movie, but it didn't need a sequel - and it certainly didn't need a second small, cute, yellow sequel. But that's what we get: a G-rated version of Deadpool with insults, coffee humour, sarcasm, and a pee joke.
Most (all?) of the complaints that follow are a result of being an adult watching a kid's movie (comparisons to "Deadpool" fall into this category as well). The writing is weak: I spotted the bad guy a few minutes after his introduction, and mostly figured out his intentions. They get a lot of mileage out of a very Inception-esque scenery bending scene ... but when you find out why it happened a couple minutes later, it makes no sense at all (yes, scenery would move - but not as it does in the movie). And yeah, this is an adult complaining about a kids movie, but is writing a kids movie an excuse to write badly and ignore physics and common sense? Pixar has never thought so. Sure, the kids don't care - but the parents who have to watch it do.
Mildly amusing, but mediocre CGI, bad logic and poor writing make this a crap movie (for adults).