It's distracting at first: the fact that you're looking at Joseph Gordon-Levitt but he doesn't look exactly like the Joseph Gordon-Levitt you've come to know and love. Aren't his eyes brown? Isn't his nose longer and thinner? Even the blasé smirk on his face seems like an unfamiliar expression given his usual likable, boyish cool.

Then Bruce Willis shows up, and you realize, a-ha! Gordon-Levitt, tweaked slightly through blue-green contact lenses and prosthetic makeup, is essentially channeling Willis because they play the same character reunited in the future over 30 years of time travel. It's not a dead-on impression or even a parody, and it's not meant to be; this is not Josh Brolin doing a younger version of Tommy Lee Jones in the most recent "Men in Black" movie. But the sighs and the cadence and the general persona are there.

So now that we've gotten that out of the way, we can focus on the really mind-boggling stuff.