Continuity mistake: When Metroman is "trapped" inside the fake observatory, he says that copper drains his power and then groans in pain. Later, during the flashback of being inside the observatory, after he says that copper drains his powers, he then looks away and starts to laugh - not how it happened before.
Factual error: Metrocity appears to be located in Michigan, but the news station on the truck starts with K, which signifies that's it's in the western half of the US.
Deliberate mistake: Regarding one of Megamind's lines when he is speaking in front of the citizens of Metro City after having supposedly defeated Metro Man: "Imagine the most horrible, terrifying, evil thing you can possibly you can think of... and multiply it by six." In the Swedish dub, the 'six' is substituted with a 'five' [most likely due to 'six' and 'sex' in Swedish having the same spelling and pronunciation, and wanting to avoid any unintentional sexual innuendos]. (00:22:10)
Answer: Mad Science. There's an old science fiction writers' saying that "Poorly explained science is better than DUMB science, " so exactly how it works isn't important, it just works.
Captain Defenestrator