Back in April I saw a show called BriTANicK: The Infinity Prison at the UCB Theatre in New York that used 4 actors, a video projector, and a time-travel plot to create a remarkably rich story for a half-hour sketch show.
The Spanish film Time Crimes (Los cronocrímenes) is similarly tight in scale -- there are only four characters (and that's something of a spoiler right there, sorry) and one extended location - Hector's house, his neighbor the scientific institute that seems to have invented a time machine, and the woods inbetween. And there's really not even that much going on, though you do get to that same not-much repeatedly from Hector's time-traveling perspective. (It's a sort of sci-fi Rashomon.)
FuzzyCo grade: A