Things aren't going well for young Oliver (AZHY ROBERTSON), a mute autistic boy. Not only does he have no friends and must contend with similar-aged bullies such as Byron (WINSLOW FEGLEY), Mateo (JAYDEN MARINE), and Zach (GAVIN MacIVER-WRIGHT), making fun of him having to communicate through a text to speech device, but he must also contend with his parents, Sarah (GILLIAN JACOBS) and Marty (JOHN GALLAGER JR.), splitting up.

Unsettled by all of that, he's easily spooked by odd noises at night. But now he has good reason to be as an invisible monster is trying to kidnap and take him into another dimension. Seemingly summoned when anyone reads a picture book named "Misunderstood Monsters" on any electronic device, "Larry" is a large, gangly monster that can only be seen through live camera shots on such devices, and with each subsequent continuation of the picture book, he gains greater access to this world. Initially unable to get anyone to believe him, Oliver must contend not only with that, but also with his world unraveling around him.

It's often hard to get kids to talk about issues that are bothering them, especially when that comes to more severe things such as abuse by family members or others, bullying in its many forms, and so on. That's not only because such victims are often too young to really grasp and process what's occurring, and usually feel that it's somehow their fault, but also due to the belief that no one will believe them, especially if it's their word versus that of an adult.

On a related but more lighthearted note, kids thus obviously never tell their parents, teachers, or any other adults about their run-ins with ghosts, demons, or monsters. After all, they've been repeatedly told most of their lives that there's nothing under the bed, in the closet, or up in the attic or down in the basement. And for kids who might be non-verbal for any number of reasons, they wouldn't be able to fully communicate what's terrorizing them, at least to the point and degree that an adult would believe.

Such is the case for our young protagonist in "Come Play," the full-length adaptation of Jacob Chase's short horror film "Larry" that actually didn't feature a kid at all. Instead, Larry is the monster featured in the short that terrorizes an initially bored but increasingly spooked parking lot attendant in his small booth at night.

And before you start to think that doesn't sound like a very menacing name for such a creature, you should check out the short. And then this film. For both are fairly effective in delivering the thrills and chills of a good ol' fashioned horror-based monster flick.

Coming off quite a bit like Danny Lloyd when he played young Danny Torrance in "The Shining," Azhy Robertson plays Oliver, a boy somewhere on the autism scale who communicates with his parents (Gillian Jacobs and John Gallagher Jr.) and others via a text to speech app on his electronic device. With no friends but a trio of bullies (Winslow Fegley, Jayden Marine, and Gavin MacIver-Wright) who pick on him, Oliver spends most of his time on various devices watching "SpongeBob" (who makes enough appearances that he should appear in the cast list).

That, his parents splitting up, and his loneliness are apparently what cause a storybook app titled "Misunderstood Monsters" to appear on said devices. It features still images of a gangly monster named Larry who has no friends but would like one, and apparently will enter our world through the portal screen of any electronic device.

And that's when things start to go bump in the night (and then some), slowly at first but increasing in intensity as the further reading of the story by Oliver (or anyone else who comes across the tale) apparently keep widening the opening from Larry's dimension into ours so that he can nab the boy and take him back.

Whether he's going to act toward Oliver like Hugo the Abominable Snowman in the Looney Toons cartoon so long ago ("Just what I always wanted. My own little bunny rabbit. I will name him George, and I will hug him and pet him and squeeze him...") or has more nefarious or culinary plans isn't clear. But Oliver, his mom, and eventually his dad don't want to wait to find out.

Chase gets good performances out of his cast (especially Robertson who creates a character you simply want to protect) and elicits terrific amounts of frights and suspense as things progressively escalate. And yes, he does manage to include and replicate to some degree the footage from the short into this cleverly expanded feature-length adaptation. If anything, it will certainly make you think twice should any picture book app suddenly appear on your device -- or making fun of a monster being named "Larry." "Come Play" is taut in delivering its thrills and chills and thus rates as a 7 out of 10.