I'd give this movie a 2/5, because this movie does have redeeming qualities but overall I feel this movie is inferior to the original.
Lets start with the pros:
-Visually this movie looks amazing, the models and pokemon and character designs look great! Apart from a few such as charizard and mewtwo. Their models aren't bad, but there is just something off about them. I prefer their 3D models from the video games.
-And another pro is I like how they incorporated later generation stuff into it such as moves and pokemon (whether seeing them or mentioning them).
But that's about it for the goods.
The cons:
-They didn't include the intro that the original movie had. It builds up the epicness of mew and by extension mewtwo and gives insight as to why he hates all humans. Without that intro the rest of the movie falls flat. They probably thought it was too dark, which leads me to my next con....
-Any "dark" material in the original is basically cut out. The intro, seeing mewtwo kill all the people on New Island, mew saying how the clones are inferior to the originals (which I know was only in the japanese version, but this was a good chance to bring it in). the fight scenes seemed way more friendly than the original. For example gyarados biting gyarados or charizard biting charizard. And when they do show it like charizard hitting charizard with his tail its slowed down to where it takes the effectiveness of it away.
-The dialogue is very rough. Now the original is far from perfect, but this is awful. They took out a lot of iconic lines from the movie, and the ones they kept in the butchered it. And quite a bit of dialogue just doesn't flow at all to where it just seems out of place.
-A minor one is when Ash is battling the trainer with the Donphan, in the original you're not supposed to know its mewtwo watching their battle. Obviously you can infer quite heavily it is, but they don't show him and you don't hear him. It just adds a layer of mystery to mewtwo whereas in this film its just "nope, here he is, no mystery at all."
-Now, while I said the visuals were amazing the animation was not. Its awful. A lot of it is robotic and doesn't flow well at all. And I'm speaking about the character and pokemon models only. The backgrounds and places were amazing. Like Pikachu running up the stairs was so slow that it felt very anticlimactic. And a lot of the models felt very clunky and not like they're actual living things.
-Lastly is the music. The music in the original is better in every way apart from one instance. I'm glad they took out that "brother my brother" song. I always felt it was awkwardly placed. But other than that, I feel the original music is better in every way.
Basically the entire time watching the movie I kept thinking, "well in this part the original movie was better." And I know people will think well, don't compare it to the original, but this movie is almost a beat for beat remake of the original. How are you not supposed to compare?