A grumpy old man with dementia is given a robot to make his life easier and they become friends. That concept should have led to a nauseating weepy made to run on the Disney channel circa 1998. But no, it was made today and somehow against all odds, it’s actually a rather sweet, charming, and enjoyable little movie. Oh, you can try to hate it, but it’s pretty damn tough. Grating sentimentality is somehow avoided and a weird heist-movie twist even make movie unexpectedly exciting. It turns out that robots and humans can actually get along after all and as long as Robin Williams isn’t let anywhere near a movie expressing that sentiment, you can actually enjoy watching the story play out.

The Frank half of the equation is played by Frank Langella, and he’s the major reason for the film’s success. Say what you will about Langella, but the man doesn’t seem to have a weepy bone in his body (kind of like a Tommy Lee Jones who you could approach without fear of having your head bitten off). Frank is a semi-retired jewel thief in the not too distant future who lives in a messy home and spends his days complaining, forgetting things, and angrily insisting that he isn’t losing his memory. His son (James Marsden) grows tired of driving out to pick up after the old man every weekend, so he buys him a robot that’s part butler, part life coach, part eerily emotionless companion (and voiced by Peter Sarsgaard). At first Frank refers to the robot as “junk” and is irritated by the humanoid appliance’s refusal to let its owner subside entirely off of Fruity Pebbles. Then he starts taking the robot out to visit his librarian crush (Susan Sarandon) and appreciates the way the machine will gently put up with his rants about the yuppie neighbors (who are the equivalent of what hipsters are now). Over time, he starts to rely on the machine as a traveling memory bank and starts teaching it his old thievery tricks. Frank’s robot-loathing daughter (Liv Tyler) tries to separate them, but Frank grows to love the machine and has a big job planned for the two of them to get some cash and avoid boredom.

There’s no getting around it, this is a buddy movie and one that rigidly follows those genre conventions. However, a buddy movie between Frank Langella and a robot is just weird enough of an idea to make the genre clichés work. Langella is a great grumpy lead and essentially carries the movie on his own next to a mechanical co-star. Sarsgaard’s voice is oddly perfect, finding that perfect HAL middle ground between emotionless speech patterns and flickers of human recognition.

First time feature screenwriter Christopher D. Ford and debuting feature length director Jake Schreier succeed by keeping things simple. The visual style is clean with minimal near-future gadgetry and the story follows all the usual screenwriting conventions. Those elements work because their film never becomes too ambitious. Even subplots involving the redundancy of libraries in the digital age and a theft of a rare copy of Don Quixote underline Frank’s condition and quest work because they’re small digressions in the narrative given the passing weight they deserve. It’s a fleeting little movie, with an emotionally harsh twist that should be predictable, yet is laid in so subtly it’ll loosen up your tear ducts before you’re aware you were so easily manipulated.

Robot & Frank may have had a Sundance premiere, but it’s a very mainstream, people-pleasing, entertainment. There’s nothing challenging about the film at all, yet by merely focusing on the carefully crafted storytelling and charismatic performances that used to define Hollywood filmmaking, it feels like more than the sci-fi drama of the week. It’s funny when it wants to be, tragic when it needs to be, suspenseful when you wouldn’t expect it, and features simple practical special effects that make the sci-fi conceits entirely believable. It’s the kind of movie you watch absently mindedly on an airplane or lazy Sunday afternoon and unexpectedly find yourself wrapped in an old man/robot buddy romance that should be so easily, cynically dismissed.  The movie won’t win awards or clean up the box office, but it will provide a smile to anyone that’ll let themselves be seduced by its charms. That’s an achievement that seems easier to pull than it actually is and a modest filmmaking success that will hopefully open doors for a new writer and director who at least seem know what they want and how to achieve it.