The Maze Runner (2014)

Awakening in an elevator, remembering nothing of his past, Thomas emerges into a world of about thirty teenage boys, all without past memories, who have learned to survive under their own set of rules in a completely enclosed environment, subsisting on their own agriculture and supplies.

With a new boy arriving every thirty days, the group has been in "The Glade" for three years, trying to find a way to escape through the Maze that surrounds their living space (patrolled by cyborg monsters named 'Grievers'). They have begun to give up hope when a comatose girl arrives with a strange note, and their world begins to change with the boys dividing into two factions: those willing to risk their lives to escape and those wanting to hang onto what they've got and survive.