The good news: Here's a lavish, serious science-fiction picture, one that on occasion transcends big-budget hit-making convention to glance audiences up against grandeur. Joseph Kosinski's Oblivion, based on his own graphic novel, is one of those futuristic puzzlers whose dramatic energies are most invested in the slow revelation of its own premise. You'll doubt the initial set-up-- it's 2077, and the Earth has been nuked in humanity's defeat of an invading alien force-- the second the hero mentions having recently had his memory wiped and that his wife has been "assigned" to him. Which brings us to Tom Cruise, the not-good news, that plot-moving app producers can download for their blockbusters but is still stuck with the usual bugs. He models sunglasses, races dirt bikes, and runs like a .gif titled "Tom Cruise Running." He's called Jack Harper-- is there a spigot in Hollywood that dispenses action hero names?―and each day he zips down to Earth from his home in the clouds, a Frank Lloyd Wright casserole dish speared atop a Jetsons pole. With the rest of our kind sent off to live on Titan, Harper traverses a ruined U.S. to monitor and repair the patrol drones designed to protect―well, what exactly they're protecting is a third-act revelation you'll just have to wonder about until Harper finally does so himself. (The Cruise app never thinks more than required.) At its best, as Harper explores a cratered library, Oblivion takes on the immersiveness of video games. Here's your cypher/avatar, picking through a wide-open alien environment, with time given for you to savor the world around you. But then come the twists and explosions.