-- Spoilers --
Great 'what if' evil Superman type story, but could have done without the gore. The kid was raised by loving parents, but my take on why he went bad was they made him too much the center of their universe. The kid was spoiled and always used to getting his way. He was raised to make everything about him and not about others. Then, about the time when his powers really kicked in, he was told no about something. He started killing, not strangers, but people who loved him, because he felt entitled to them doing anything he wanted. That's not exactly what the movie showed (it showed a scene or two with the spaceship and voices that might be taken to imply the voices just turned him evil for no underlying reason, just like a switch) but my take gives a much deeper meaning and insight into his mind. However, the movie may not have "intentionally" implied he was raised a selfish brat. But the scenes they showed, even at the start before he was all kill-y, kind of skipped over any form of discipline or real conversations about bad behavior. Which implies he's NEVER had any. It definitely implies he's the total center of their universe however.
I really liked it. Just a tad too graphic on the deaths and it didn't need to be to still have a nice creep factor. I would love more movies like this. In fact, there was even a crazy Lex type at the end who might be the best hope to stop the crazy self centered Brandon.