The only leeway that a sci-fi or fantasy movie/show should get is the initial underlying concept forgiveability.
For example. Marvel Universe is full of individuals with abilities that break laws of phsyics, are unrealistic and could never exist in the real world. The idea that those individuals can exist is the underlying concept of the Marvel Universe so you can forgive the unrealistic nature.
Just because those powers exist does not mean that you can break rules that exist within the Universe itself without a really good explaination. Wolverine is nearly immortal, has adamantium lined bones, claws, and felion like senses and agility. People know this, and as illogical and impossible as it is, they accept it. However, if Wolverine starts flying around, shooting laser beams from his eyes and turning into living metal, he better damn well be a skrull or it makes no sense.
Long story short, Even if a universe has unrealistic laws, it still has to have laws, or it becomes too random. heroes, for me is on the verge of proving that it has no laws or universe definition.