Breathing Room (2008)

After awaking in a dark closet with a corpse, Tonya (Ailsa Marshall) opens the door to a room full of strangers. At first, it seems, their only similarities are the prison uniforms with which they've been provided and the electric-shock dog collars around their necks. But, as their time together continues, they realize they're all part of a sick & twist game involving rules by which they must all abide and a series of clues they must solve in order to, possibly, find freedom and answers. The fight begins when 'curfews' start and, one by one, the players are eliminated