Every few years, Robert De Niro likes to mix it up. He’ll throw in “Last Vegas” or “The Intern” to remind us all he’s more than Travis Bickle or Jake LaMotta. He can also be a generic old man with a deep voice and a contract that requires him to wear reading glasses for 70% of the movie. And so arrives “The War With Grandpa,” an adaptation of Robert Kimmel Smith‘s 1984 novel, directed by animation veteran Tim Hill, with a script by Matt Ember and Tom J. Astle.

READ MORE: ‘The War With Grandpa’ Trailer: Robert De Niro Battles A Little Kid In The New Comedy Film

“The War With Grandpa” begins as you might expect. After losing his wife to cancer, Grandpa Ed (De Niro) moves in with the family of his daughter Sally (Uma Thurman). She and husband Arthur (Rob Riggle) give their son Peter’s room to Ed, banishing the boy to an attic crawling with rats, bats and spiders. Peter (Oakes Fegley of “Pete’s Dragon“), who supposedly loves his grandpa, declares war on the loving, sweetly aging patriarch, attacking him with drones and loud noises at night.

One imagines there is someone who finds that premise amusing. This critic didn’t laugh at a lonely, heartbroken grandpa taking a hard fall, then waking up the next morning with a bruised leg–just because some brat wants his room back. But Ed isn’t going down without a fight, and he enlists senior pals Christopher Walken, Cheech Marin and Jane Seymour to join the (A)ARP-Team. The team is no match for Peter, or his pals Steve (Isaac Kragten), Billy (Juliocesar Chavez) and Emma (T.J. McGibbon), but it sure seems like everyone’s going to take some hits and learn some lessons along the way.

It goes without saying that the film is childish, playing fast and loose with hijinks such as gas, nudity, toe fungus and toilet humor, not to mention the treatment of old people as old farts. But none of this is rendered in a particularly funny or novel way–just crude, eye-rolling gags. Therefore, the film isn’t suitable for kids or adults.

Much of “The War With Grandpa’s” humor tries to split the difference. There are meta-jokes for adults, including a scene of De Niro talking to himself in the mirror. There’s a moment of excitement when De Niro and Walken team up for a game of dodgeball, a very different game of Russian roulette from the one they played in “The Deer Hunter.” That excitement dissipates, though, as the two legends are flanked by an enemy worse than death: poop jokes.

Despite its family-friendly premise, nothing is kid-friendly. Beyond the fact that many of these gags are gross and predictable, there’s a meanness to the film that’s at war with the feel-good tone. It’s probably a stretch to get viewers to sympathize with a kid who attacks his grandfather because his room is, what, five feet bigger than the attic? The traps are lame compared to “Home Alone.” The relationship between Sally and Arthur is awkward, while Ed and Peter’s inevitable bond feels contrived to give this a happy ending.

Bright spots are found in the supporting cast, though the less said about Faizon Love‘s portrayal of a black belt grocery clerk, the better. Walken is legitimately great as an old guy trying to be hip, a sort of exaggerated version of what Thurman is doing as the cool but protective mom. They just aren’t enough to pull “The War With Grandpa” and De Niro out of the gutter. Stay home and watch “Raging Bull” instead. [D+]