While in detention they discover that the school's stuffed bear mascot is actually a time machine and that the world is supposed to end in 1992 as a result of Ione's mother Sloane refusing to go to prom with Verge.

[11] Justine Elias from Slant Magazine gave the film 3/4 stars, writing, "For gorehounds lured in by the poster and trailer, Detention will be disappointingly un-gorey.

gave the film a positive review, writing, "Smart, funny, and equally full of splatstick violence and heart, Detention isn't just next-level horror--it's next level everything, a senses-altering reaffirmation of cinema.

Shafer from IGN called it "a shockingly meaningful, potent film about the nature of meaninglessness and its damning effects on the younger generation".

"[15] Nicolas Rapold from The New York Times gave the film a negative review, writing, "Another entry in self-conscious one-upmanship, Detention is a horror comedy positively addled with retro references.

"[16] Peter Hartlaub from The San Francisco Chronicle hated the film, "There will be young moviegoers who proclaim this genius, and more stodgy audience members who find it torturous.

London's Frightfest gave it the Biggest Surprise Award and organizer Alan Jones named Detention as his overall favorite film of the festival in 2011.

"[21] Quint of Aint-It-Cool-News raved "time traveling teen pop culture comedy Detention is a runaway freight train of frenetic energy!

"[23] Kevin Sommerfield from Slasher Studios also gave it a glowing review stating the film "is Scream meets Scott Pilgrim with a dash or two of Kaboom, it makes for one wild cocktail.