As its title suggests, "Possible Worlds" is a film about the possibility of infinite parallel worlds, but if you're expecting some kind of Hollywood-style CGI extravaganza, you've come to the wrong place: it is a low-budget Canadian film and the special effects are minimal. Nevertheless, it invites you to soak in its dreamy, fluid images. As he proved in his writing-directing debut, "Le Confessionnal", Robert Lepage is a wizard especially at scene transitions. Both films are ambitious and interesting, if not 100% successful. But, as an old saying goes, sometimes an ambitious "failure" is preferable to a safe "success". Tilda Swinton is captivating, as always. **1/2 out of 4.