Let me be very frank: the movie is a little jarring if you are a longtime fan of the show. The show already kind of has an origin story episode, so watching the movie is like watching a reboot or remake of a story that hasn't even finished yet. You really have to see this movie as it's own thing, removed from the show. The animation is fantastic, I'll give it that. I think that is the reason I gave it the amount of stars I gave it. In it's own right it is a decent movie. It just doesn't feel like Miraculous Ladybug. It's missing the humor and quirky parts of the show. Gabriel Agreste and Hawkmoth are the only characters that are recognizable in the movie. The other characters feel so far removed form the series that I have a hard time believing they are the characters I see in the show. If they didn't have the same name and look, I honestly wouldn't recognize them. And it sucked that we didn't get Cat Noir's iconic transformations nor Ladybug saying "Miraculous Ladybug" when Ladybug restored everything (which was a let down because that would have made the scene more impactful as a fan).
Another aspect of the movie that weirded me out was the singing, particularly Marionette's in the English dub version. Her singing voice is absolutely nothing like her voice actor's voice. She's a great singer, but it didn't feel like Marionette was singing at all. Normally I can't tell the differences between singing and voice actor, but these two were so different it threw me off. Personally, the movie would have been better without the music. This was not the kind of movie that needed it.
I think this movie will be enjoyable for first time watchers or for people who are not really a fan of the series. It might also be enjoyable to those fans who are too impatient for things to unfold in the series. But for those of us who greatly enjoys the show, it's meh.