If shows such as The X Factor have you itching for the smell of the greasepaint, The World As A Stage offers more than a whiff. Yet Tate Modern's new exhibition might serve to put off limelight-seekers, presenting, as it does, a peculiarly alienating vision of performer and audience alike.

The opening series of drawings depict artist Roman Ondak wandering through the empty gallery. They were made by 24 non-professional artists, who based their drawings of Ondak on nothing more than the curator's description of him. Collectively, they heighten our own awareness of the way we move through the space. That feeling of aimless choreography continues throughout different works, placing you centre-stage in a performance that only you are watching.

Jeppe Hein's Rotating Labyrinth refracts visitors in a mirror, multiplying them into audience members catching glimpses of themselves. In Séance de Shadows II by Dominique Gonzalez-Foerster, a set of bright lights is triggered as you move through a carpeted room. Your silhouettes unwittingly help create a flickering cinefilm-style procession on the opposite wall and, like actors, you have to blink back the glare if you stare at the lights too long.

The exhibition suffers by not continuing that Truman Show theme throughout; instead, it mixes up works that turn you into protagonists, with others that explore the interaction of theatre and visual art. Jeremy Deller's installation is fascinating, comparing clashes in the 1984-85 miners' strike with historical re-enactments of battles, but in truth it's a completely self-contained show.

Similarly, by cramming in so many contrasting performances, The World As A Stage weakens the resonance of individual works. Geoffrey Farmer's Hunchback Kit includes a film of the artist ringing a bell in a forest - but if the bell makes a sound, it is drowned out by Catherine Sullivan's video on a screen in the next room.

That screen is set up opposite another piece diluted by positioning. Rita McBride's Arena is a large, mobile seating structure, shaped like an amphitheatre. Its original incarnation was placed overlooking a Rotterdam gallery's administration offices, drawing attention to what happened behind the scenes. Now it has been given a much more traditional purpose - to provide a platform for performances during this exhibition and to turn us into passive viewers - much of its significance is lost.

Yet you still have to walk across the empty space between spectators and screen to reach another room, temporarily adopting the self-consciousness of the watched. It's those moments which create coherence in an otherwise disparate collection.

Until Jan 1, Tate Modern, Bankside SE1, daily 10am to 6pm (Fri and Sat to 10pm), £7 (£5.50 to £6 concs). Tel: 020 7887 8888. www.tate.org.uk Tube: Southwark/Blackfriars.