SPOILER

I really loved how they depicted Mewtwo that was really well done and it really connects with me as a long time fan

I really felt like I was experiencing mewtwo as I imagined him as a kid

My only gripe was the ending sequence was a bit shallow compared to the original movies.

In the end it reveals that Mew Two said "Humanity is evil, but you showed me that not all humans are bad"

Where in the First Movie he says "I see now that the circumstances of one's birth are irrelevant. It is what you do with the gift of life that determines who you are."
I am not saying they should have copied the original movie but I feel like some more thought could have been put into that line. It was kinda anti-climactic. But that's my only complaint truthfully.