There are some 40 people in the play and Ferguson voices all of them, from a mafia wiseguy to an imperious Bon Appetit magazine staffer, to an 86-year-old furniture maker to a Park Avenue socialite. He goes from stuffy French to surfer-guy cool in milliseconds. The 90-minute show...is a triumph of voices and athleticism from Ferguson...The amount of concentration required by Ferguson is impressive and director Jason Moore runs a tight ship. One stray ring or bobbled cue could set the whole thing off, but Ferguson runs through "Fully Committed" surefooted like an Olympian on an obstacle course.