The hardest part about reviewing this movie is going to be avoiding the word “adorable.” An observant, one-inch-tall talking shell lives a colorful existence with his grandmother in an Airbnb, the sole survivors of a mysterious tragedy that wiped out their once-vibrant community. Fate steps in when documentary filmmaker Dean Fleischer Camp discovers and makes a short film about them.

True story: that 2010 stop-motion short became a huge hit. And, nearly inevitable these days, it was thought that a feature-length continuation of the little guy’s observations and adventures would be a great next step. The surprise here is that, for once at least, bigger is better.

Not enough can be said about co-writer Jenny Slate’s voice work as the title mollusk, peaking out with Marcel’s devastatingly ado…um…tender acapella rendition of “Peaceful Easy Feeling.”

The short’s viral publicity earns Marcel millions of fans and brings varied results, the biggest deal being (shyly and reluctantly) interviewed by Leslie Stahl’a on “60 Minutes.” Leslie Stahl’a is played by Leslie Stahl’a.

This is simply a wonderful film. A true original that even melted a hardened cynic like me. It’s weird, funny, sad, clever, and smartly written, offering new perspectives, perhaps on your own world. One tangent serves as a gentle, kid-friendly analysis of loss, grief and community. All this will take on your part a willingness to believe, but that’s very easy to come by. It’s simply… just… just…(oh, what the hell!) adorable! (90 min)