The indie comedy-drama “Ruby Sparks” has some nice moments, some good laughs and some great performances. But the film never quite delivers on its too-familiar premise, and in the end commits the cardinal sin of movie-making: It tells you how to feel.

The film’s central conceit sounds like something out of a freshman creative writing class. Novelist Calvin Weir-Fields (Paul Dano) is a 20-something boy wonder whose first book was a runaway literary sensation.

Suffering from a debilitating case of writer’s block, Calvin takes the advice of his shrink (Elliott Gould) and proceeds to write about the girl of his dreams, whom he names Ruby Sparks.

The next morning, Ruby (budding star Zoe Kazan, who also wrote the script) simply appears in his kitchen, making eggs.

Understandably, Calvin proceeds to freak directly out. This is maybe the movie’s funniest sequence as Dano, with his long-limbed gawkiness, delivers some terrific physical comedy, literally bouncing off the walls before folding himself under his desk.

Ruby is a dream girl, all right – beautiful and bright and funny. She’s also quite real. Paul has somehow written his perfect girlfriend into existence, complete with her own memories and back story.

Calvin soon discovers that others can see Ruby, too. His brother Harry (Chris Messina) drops by with family in tow, and becomes Calvin’s only confidant as to the curious nature of his new girlfriend.

From here the film toggles between comedy and drama as Ruby and Calvin settle into their domestic routine. Kazan (granddaughter of the great director Elia Kazan) is a natural, joyful performer – she has the winsome, slightly spaced-out energy of Zooey Deschanel or Miranda July. Dano is an infinitely flexible actor – his expressive face can flash from goofy to scary in an instant – and he presents Calvin as an essentially good person capable of very selfish behavior.

When Ruby starts to show some independence – hanging out with new friends and spending nights at her own apartment – Calvin does the thing he swore he’d never do. He writes Ruby back into line, transforming her into an obedient girlfriend with a few sentences on his old-school manual typewriter. The dread starts to slowly build as the film ventures into the darker aspects of its scenario.

Dano and Kazan have one harrowing scene together in which he yanks her around, existentially speaking, as she stands in front of his writing desk. It’s creepy and effective, but “Ruby” is best in its lighter moments.

There’s a great set piece in Big Sur when Calvin finally takes Ruby to meet the parents. Annette Bening has a ball as Calvin’s mom, a blissed-out hippie living the good life with her organic vegetables, erotic art and sexy sculptor boyfriend (Antonio Banderas).

The movie’s final scenes are a disappointment. For most of its running time, “Ruby” plays fair by the rules of its own premise. Kazan’s script resolves the paradoxes it needs to, and deftly avoids the others. In the end, though, we’re given a scene that essentially amounts to audience instructions. We’re told to suspend our disbelief and roll with it.

That said, “Ruby Sparks” is certainly superior to standard studio rom-com fare. Aside from the unfortunate ending, the movie respects the intelligence of its audience, and co-directors Jonathan Dayton and Valerie Faris keep the pace brisk and engaging.

If for no other reason, see “Ruby Sparks” for the supporting roles. Bening is a delight, Elliott Gould makes a perfect shrink, and British veteran Steve Coogan has fun sleazing around as a jealous rival novelist.