Countdown can never be taken seriously enough to work as a conventional horror thriller, and it’s never quite funny enough to be a great horror comedy. But it’s got just enough eccentricity and self-awareness to entertain despite those obvious deficiencies.

This isn’t a subtle, moody film filled with a sense of unease; instead, jump scares are around every corner. If that’s all you want from a horror movie, you’ll have a very good time — and an elevated heart rate for its speedy 90 minutes.

The movie arrives at an eye-roll inducing final twist, and hints at an inevitable sequel. But this app isn't exactly begging for an upgrade.

It’s not highbrow entertainment. Movies like this always feel “designed,” like a theme park ride — story beat, JOLT, exposition exposition JOLT, etc. But Countdown manages the bare minimum — the occasional shock, characters we root for, thanks to the actors playing them, and situations fraught enough that the audience is talking back to the screen.

A pedestrian thriller whose personal-tech gimmick is even more thinly imagined than one might guess, it's a jumble of cheap jump scares made watchable by likable leads Elizabeth Lail and Jordan Calloway.