1. Edge of Tomorrow is such a terrific idea for a movie that everyone involved seems to be in high spirits, like they all have a little pep in their step knowing they're making a good movie. There's so much junk out there that you can tell when the filmmakers know they've hooked a big one; there's a seriousness of purpose, a quiet grin of satisfaction on everyone's faces. Sometimes, an ad man just takes pride in having a good product to sell.
2. The idea is so simple it's amazing it took this long: Groundhog Day, but a science-fiction war film. Tom Cruise, as relaxed and loose as he's been in, jeez, a decade, plays William Cage, a PR hack who ends up working media relations for the military in an ongoing war with some sort of alien squid monsters. (The movie's timeline is a little confusing: It takes place in a future where we've been fighting aliens for years, but also features Hillary Clinton and Barack Obama and various current television personalities.) As punishment for attempting to blackmail a superior officer, Cage is sent to the front lines and stripped of his rank, doomed to be killed in battle. As it turns out, though, when his inevitable death comes, he is snapped back to the beginning of his day, forced to relive it, Phil Connors-style, until he can figure out what's going on, and somehow win the war.
3. Edge of Tomorrow doesn't have the philosophical underpinnings of Groundhog Day, which was more concerned with figuring out the right way to live than accomplishing concrete goals like winning a war against alien squid monsters. But it's a perfect premise for an action movie, because we get to watch as Cage gets better and better at killing, at learning what's going on around him, at discovering what, exactly, these aliens have in store for us. (It's also funny to watch him talk to bewildered onlookers, compressing exposition that it took him decades of one day repeated over and over to discover. Imagine needing someone's help to kill aliens, but you have to re-introduce yourself 45,000 times.) It helps that he meets a fellow soldier named Rita (Emily Blunt, who's great) who has been through the same thing, and understands what they have to do. The movie is intricately plotted in a way that's unusual for a summer blockbuster: It sets up the rules for this universe and then dutifully follows them, and the logic of every situation, to the letter. It's a treat to watch a movie that doesn't cheat.
4. I know you've probably long since made up your mind about Tom Cruise, and his roles like this in which he always seems to be running. I personally consider his insistence on being the last remaining movie star to be downright honorable, particularly because he's so solid and relentless at it: You know you're going to get his all every time out, even when it would seem insane to give it to you. He's impressively light on his feet here, appropriately weaselly at the beginning and progressively more heroic (while still baffled) as the film goes along. It's a tough job, being a star like this, having to anchor every movie every time out, and there's nobody better at it. (This is also one of the first Tom Cruise movies to acknowledge his age, at least briefly.) If you can't let go of his off-screen weirdness (and even that's a bit overstated) and enjoy Tom Cruise's eternal onscreen Tom Cruise-ness, you're only depriving yourself.