The behemoth of the box office this week, of course, is Oz the Great and Powerful. Billed as a prequel of sorts to the 1939 classic The Wizard of Oz, Oz the Great and Powerful stars James Franco as Oscar Diggs, a circus magician/scam artist transported via twister to the Land of Oz. There, he encounters three witches—Theodora (Mila Kunis), Evanora (Rachel Weisz) and Glinda (Michelle Williams)—who believe he may be the long-awaited great wizard the people of Oz are expecting. As he’s drawn into Oz, Oscar has to figure out who to trust and whether or not he can be the wizard Oz needs.

For his first big follow-up to the Spider-Man trilogy, director Sam Raimi reunites with Franco for what Disney clearly hopes will be a successful continuation of familiar source material, akin to 2010’s Alice in Wonderland. Franco, however, is no Johnny Depp. Franco was not Disney’s first choice for the role (Robert Downey Jr. and Depp were Disney’s first two picks before Franco landed the role), and watching the film, one wonders what might have been if either of Disney’s other choices taken on the role. At this point in his career, Franco’s taken on a certain public image that inevitably overshadows his film roles, and in the broader moments of Oz, Franco can’t make a distinct character. It feels like Franco’s playing make-believe.

Oz is also harmed by the altogether inappropriate casting of Mila Kunis as Theodora, a.k.a. (SPOILER ALERT) the Wicked Witch of the West. Kunis is decent enough in her first scenes as the innocent Theodora, but once she’s transformed into the purely evil Wicked Witch, Kunis is out of her depth. Not even taking into consideration the far superior performance by Margaret Hamilton in the 1939 film, Kunis just doesn’t have the chops to pull off the anger and evil of the character.

Where the film does well is in its visual effects. Considering the technological advancements since 1939, Oz is a vastly magical improvement in its portrayal of the Land of Oz. Even the film’s portrayal of Kansas (presented in 4:3 Academy ratio in black and white, drawing comparisons to the original film before expanding to a 2.35:1 ratio for Oz) is a wonder, with the presence of the twister being especially entertaining. Oz is worth watching for its visuals, but as a story, a stronger cast would have made this a far more enjoyable viewing.