‘Grandma’ was a project conceived to highlight the distinct talents of Lily Tomlin and is worth watching exclusively for her performance. She commands the screen and walks all over any actor who dares join her. It’s a wonderfully prickly turn and an amusingly barbed character that hasn’t really been seen before.

Unfortunately, the movie surrounding Tomlin often can’t live up to her stellar work. But at least she’s there to highlight what could have easily been something much more forgettable.

Tomlin stars as Elle Reid, an ex-poet and early feminist who delights in spouting off cutting insults at high speed in every direction. The film opens with her breaking up with her girlfriend (Judy Greer) after a brief four-month liaison. It’s a harsh breakup clearly designed for Elle to tear herself free before she gets deep enough to be vulnerable. From there, elle’s granddaughter Olivia (Julia Garner) pops up unannounced, recently pregnant and looking for help to pay for an abortion. Elle agrees, but doesn’t have the money herself. So she heads out to visit her few remaining friends with predictably disastrous results, plus intergenerational bonding (obviously).

The film comes from writer/director Paul Weitz, who started his career in the mainstream comedy realm with flicks like ‘American Pie’ and has been trying to ease into more indie fare ever since. His best film in that regard is likely ‘About a Boy’, which ‘Grandma’ tries to be an equivalent to in its mixture of rude comedy and warm emotion. The deliberately episodic structure matches those tones with mixed results depending on whom Tomlin’s sparring partner is in any given scene. At its low points, the film tries far too hard to tug on heartstrings and gently touch on big issues without exploring them too deeply. There’s a harsher and richer film buried somewhere in here that Weitz keeps at arm’s length through schmaltz and laughs. The latter is welcome, the former not so much.

The best sequences can be rather wonderful, though. Julia Garner offers just the right combination of naivety and cynical intelligence to match Tomlin’s wit while still standing gracefully under her shadow. Sam Elliot has a nice sequence as one of Elle’s former lovers that starts with gentle teasing and ends with old wounds torn open. It feels like a strong short film in and of itself. Plus, when the mother between the central grandmother/granddaughter team is finally revealed to be Marcia Gay Harden, it’s clear that we’re in good hands and the bitter bickering with gooey emotions will only get stronger.

On a scene-by-scene basis, the movie can be quite strong and serves up a nice mixture of aching drama and bitter comedy. It’s only on a macro level that ‘Grandma’ feels a bit too slight and manipulative.

Still, there’s far more good than bad here. Tomlin is such an absolute delight from the first frame until the last that’s it’s almost impossible to tear your eyes from her. The character takes advantage of her comedic timing and rarely explored dramatic depths. While Weitz may sneak some sentimentality into his story, Tomlin doesn’t let any of it taint her performance. She’s always sharp and on-point, never dropping a single comedic barb or losing sight of her character’s tragically flawed core. The way Tomlin’s performance and character undercut the gooey emotional warmth at all times actually saves Weitz’s film from itself. ‘Grandma’ might not be a masterpiece, but it’s just unpredictable and honest enough to be worth a look.