Time travel can't stop your kids growing up, in Mr. Peabody and Sherman

We haven't had a good time travel movie in ages. I guess Looper was the last one. But Mr. Peabody and Sherman, out today, is a lovely time travel film, that has fun with the conventions of the genre. And it tells a unique story about how mastery over past and present doesn't save you from the heartbreak of your kid growing up.

Some minor spoilers ahead...

Mr. Peabody and Sherman updates and expands a series of cartoon shorts from 50 years ago, that appeared as part of the Rocky and Bullwinkle show. The basic setup is pretty simple: Mr. Peabody is a supergenius talking dog, who's invented a time machine, and he takes a young boy named Sherman on adventures throughout history.

For the movie version, these thumbnail-sketch characters are fleshed out, and their relationship is clarified. Turns out Mr. Peabody was a super-mutant dog who didn't belong with the other dogs, and his accomplishments were nearly limitless until he discovered a human baby and decided to take on the ultimate challenge: fatherhood. Now, the dog is raising a human child, and facing all the normal challenges of taking care of a kid, plus a few extra ones.

Time travel can't stop your kids growing up, in Mr. Peabody and Sherman

When Sherman goes off to school for the first time, there are two conflicts set in motion simultaneously: Mr. Peabody has a hard time dealing with the fact that his adoptive son is growing up and becoming an independent person. And Sherman gets teased about the fact that his father is a dog, and winds up biting Penny, the school's main "mean girl" — which leads, in turn, to Child Protective Services being called to assess whether Mr. Peabody is really a fit parent to a human child.

To its credit, the movie juggles these two conflicts, which are very different in nature and tend to go in almost opposite directions, without ever losing its balance. In fact, the movie plays the two conflicts (letting go versus proving your worth as a parent) off against each other, in a way that's sometimes quite clever and also emotionally enriching. A lot of animated films barely manage to sustain one conflict for 90 minutes, but Peabody successfully keeps two boiling over. Not only that, but it works these two opposing conflicts into an entertaining, coherent time-travel story. Which is no mean feat.

Time travel can't stop your kids growing up, in Mr. Peabody and Sherman

And the movie's handling of the time-travel stuff is deft and fun and clearly owes a lot to films like Back to the Future and the Bill and Ted duology. Meddling in history turns out about as well as it usually does, and there are the requisite number of time paradoxes and temporal pratfalls. Fixing the space-time continuum dovetails pretty neatly with fixing both Mr. Peabody's relationship with his son and his tricky status in the eyes of the law.

It all leads up to an emotionally powerful scene that is pretty much guaranteed to make you cry your eyes out, which respects the complexity of the themes this film has been tackling, and packs a clever solution to the film's central time-travel dilemma.

A lot of time travel films are about loss, or the potential for loss — Safety Not Guaranteed does a lot of great stuff with this — but relatively few time-travel stories deal with the inevitable loss that a parent experiences watching a child grow up, along with the fear of losing a child. Mr. Peabody takes a very light-hearted approach to exploring history and dealing with time paradoxes, while giving the full weight to the terrible things that time does to the parent-child relationship.

Time travel can't stop your kids growing up, in Mr. Peabody and Sherman

Now for the bad news: The humor in this movie mostly falls flat. Not horribly flat, just kind of flat. Most of the jokes are duds. There's an excessive corniness to the puns and verbal jokes — although a lot of the slapstick comedy with our heroes running around the past is highly entertaining, and plays off the bracing visuals in a fun way. Still, most of the jokes and gags in the film are bland and fail to achieve their meager ambitions. It's not as bad as the endless recycled mother-in-law jokes in The Croods, but there may be a certain amount of eye-rolling at the humor in Peabody.

It's weird that a film that's so smart, in so many ways, settles for such dumb, under-achieving humor. Every now and then, a clever gag does sneak through — like a running joke about Leonardo da Vinci's creepy baby automaton, for example. And the meta-joke (which is in all the trailers) where Mr. Peabody brings a mini-Trojan Horse inside the Trojan Horse is pretty brilliant. Plus several moments are cute, even if they're not actually funny. Plus Stephen Colbert and Mel Brooks, among others, lend a welcome zing to the voice cast and it's fun to play "spot that comedian" among the minor characters. And the film seems like it's going to veer into fat-shaming humor at one point, only to zig-zag into something a darn sight better.

Time travel can't stop your kids growing up, in Mr. Peabody and Sherman

All in all, Mr. Peabody and Sherman is a film you can take your kids to, without being bored or annoyed — it's no Lego Movie, but I'd say it's competitive with Frozen in terms of general watchability. Parents will resonate with the well-thought-out, emotionally honest treatment of the bond between a parent and a child, and all the insecurities that come with it. And time-travel nerds will be amused by the temporal shenanigans.

It all adds up to a film that shows how time travel can be used as a metaphor for nearly universal experiences. In the end, in Peabody and Sherman, the tangled relationship in which a child outgrows a parent, who's striving desperately not to fail at parenting, is the greatest paradox of them all.