*THIS REVIEW MAY CONTAIN SPOILERS... OR MAYBE NOT. THE WARNING IS THE SAME FOR ALL*
It's a trick question, you all know it.
It seems some scientists made a clone from Mew's DNA (Mew being an "extinct" Pokemon) and named it Mewtwo (originality at its best). But of course, reckless management of engineering finally hit pay dirt and Mewtwo ends up killing people and hating humanity as a whole. Ash, the hero of the show the movie's based on, receives an invitation to a solitary island to meet some Pokemon Master. He and his friends, and other trainers too, arrive at the island and find that the master is Mewtwo itself, who plots to create copies of their Pokemons and use them to take the world and rid it of humans and pokemon "slaves" alike.
These reviews are the hardest to make: the ones about series. I mean, they're obviously made thinking in the series' fans. So, they throw aside all the characterization inherent in a movie, because it has already been showed on the show (quite redundant, huh?). Similarly, the overall plot is also assumed to be known. Because of that, these movies obviously are poorer in development than the average.
I recognize I watched the show for some time (not a fan, I HATE that word... fanatic, yuck), so the basic premise and the protagonists were familiar to me... besides, I've played the game enough to know who Mewtwo was without needing the movie's explanation. But I'm trying to make a review about the movie, not my previous knowledge; and referring to that, the movie is somehow difficult to follow for an adult: we know from the initial sequence (if you see the uncut version... otherwise, well, sorry) that Mewtwo is the villain in the movie. You can assume Ash and company are the heroes because... well, they just seem the hero-type to us. But where the hell does that Team Rocket stand? Seeing the anime we know they were SUPPOSED to be the antagonists, but ended up being some kind of comic relief. But in the film they appear out of nowhere, sometimes acting as good guys and sometimes acting like morons, without explanation of who they are or what are they doing there.
Visually, the movie has very interesting effects. Some of them are just to show the state-of-the-art technology and are therefore annoying. But for the most part, they help to make the endless battles watchable.
The storyline? It's an excuse for making a movie, obviously... but it's actually based (kinda) on the game, so it's not really a cockamamie plot created in a brainstorming session or something.
The final verdict? Let's put it this way: when it was shown on the cinema, it was a tie between the public, because half of them were children who loved the show, ergo they loved it, and the other half were the parents who went with them, and they probably fell asleep after the first ten minutes.
Something I gotta say, though: reading Roger Ebert's review about this film, he said something about no one being able to explain the concept, not even the fans of the show. Well, I don't want to sound like a know-it-all, but it's not so difficult to understand. It's very similar to collecting bugs, but these ones are actually alive... and you use them in battle.