Well, from the 2 seconds we see of Charmander and the 3 we see of Charizard, they actually look pretty good. I was honestly expecting them to look more lizard like, but they managed to make them look semi-realistic with fairly un-lizard like eyes, so yeah, that gets a big thumbs up from me.
It seems like they're not taking this movie too seriously but still trying to keep it faithful to the franchise and fun. It felt weird and a bit funny to hear Pikachu say "Oh my God", but saying "Oh my Arceus" might have been confusing for some people, so I get that. It's clear they've done research as shown with that Mr. Mime bit, which made me realize that we've never really seen Mr. Mime act like...a mime in the games or anime out side of waving their hands around in circles. And am I the only one who thinks it looks less creepy here then in the games? Probably.
As for the models, some look pretty good (Charmander, Bulbasaur, Pancham), some look serviceable (Pikachu, Jigglypuff, Mr. Mime), and some look...a bit off (Psyduck, Graveller, Greninja), but that can be expected. Making a Pokemon appear realistic without being creepy is no doubt hard to do. Honestly, so long as the writing's good, it'll be fine as it currently stands.
The tone seems to be more "for the whole family" instead of "for kids" with a few dark moments and a bit of adult humor thrown in that you don't see in a Pokemon movie. So long as it doesn't turn out to be a massive dumpster fire that even a hardcore fan couldn't enjoy (ie: like The Last Airbender for Avatar fans), I'll definitely go see it.