I can sum this one up pretty easily: It's a bad movie but a great Monster Hunter movie. I loved it and will recommend it to every MH fan, but I also have many criticisms.
If you're a fan of the series, you are gonna love this. If you're not a fan or are unfamiliar with the series, you're gonna be bored and/or confused.
Firstly, this movie doesn't hold your hand and go into great depth explaining the MH universe; it kind of assumes you already know more or less how the world works, what monsters are, and what a hunter is. Again, as a fan, I appreciated jumping straight into the story without too much exposition, but a newbie will miss out on a lot of references and nods to the games.
The animation was a mixed bag for me. The humans have a weird Pixar/Dreamworks feeling imo, and over-emoted a lot of the time (possibly to make up for the very simplistic facial expressions). The monsters, on the other hand, looked fantastic--not super realistic, but nicely detailed, and fans of the series will notice that monsters move just like they do in the games. Deviljho in particular was a standout for me, and Lunastra's flames were gorgeous. Some of the weapon animations were stiff, but again you'll be able to compare a lot of them directly to the in-game moves.
The voice acting was.... well, it's what you'd expect from a low-to-mid-tier American voice acting cast. Some were okay, some were meh, some were annoying. Again, quite a bit of over-emoting. Definitely a weak point imo, although none of it was bad enough to really distract me from the action.
Unfortunately this is quite a short movie, and it suffers from poor pacing as a result. There is very little character development, virtually no down time between action sequences, and fights are over quickly. But it left me wanting more instead of regretting what I had already watched, and there's a lot to be said for that.
This movie felt like a love letter to fans of the series. I was constantly noticing little nods to things you see in-game, from how things were crafted to moves the monsters used to the delightful little Kinsect. It was imperfect but exactly what I wanted out of a Monster Hunter movie.