I just have to react on this one.
I'm a huge fan of Pokémon myself and I found myself disliking this movie.
The 30min intro-movie was great I thought. I was hoping for another action/animation movie with Mewtwo in it. This movie doesn't contain the same Mewtwo, it's not only another voice actor (actress) but it has also a more 'round' female face. In my memories mewtwo was created by men (it (she?) reminds us about that every time she talks) and there's only one of it (her?).
The Genesects are not bad, their search for their home is bad. Just like Palkia, Dialga, Deoxys, and the later movies it's the same story about finding a home. It's where Pokémon the movie started with aswell.
The animation was great, Ash and his friends who realy weren't of any help had too much screentime for the storyline but compared to the Pokémon movies I know it's too little Ash and too much 'I'm Mewtwo and I'll save you because all other Pokémon are weaklings.' There's a lot of screentime for the Genesect but they don't dive into how they're made (and modified) from fossils and who did it. It's only one sentence somewhere in the movie.
I'm used to the voices in Japanese ánd English Pokémon and they are both done very well. English is not as good as Japanese though. The only voice I hated was the 'friendly' Genesect's; It made me think of the annoying flying dog/buglike Pokémon in Giratina's movie. I forgot his name since I really disliked him.
There's no character Development as usual but that doesn't annoy me anymore since I can't think of Ash as 25years old. To me he was like 16 from the start and he still is. I know he's only 10 years old but that has always been impossible in my mind. It's better the way I see him I think.
If you want to see Pokémon through my eyes you've got to go back to the place where Tentacruel destroys a city and Charizard is fast and strong enough to make it almost into space (pidgeot is the only one who actually made it) and he can catch anything he wants to if it's falling down from up high.
Last but not least, -sorry for being so skeptic about changes in the series, What's happened to Chansey??? I can handle the anime's different Nurse Joy helpers like Wigglytuff and Blissey on occasion, but Audino as standart is too much for me.
Overall, the movie is not bad for kids from today, it's not a movie for Pokémonlovers from the first generations.