Ashton Kutcher is a goofball. There are no two ways about it. From bumbling around as the clueless Kelso on That ‘70s Show to attacking his well-to-do friends on the ubiquitous Punk'd, this guy has made a hell of a living being wacky. Kutcher's noogie-giving persona does exude a confident charm, however, and that charm goes a long way in The Butterfly Effect, the heartthrob's first dramatic lead since he hit the cover of Tiger Beat.

With his innocent smirk and sincere delivery, Kutcher (who also executive produced) brings a fun simple honesty to this alternate-worlds thriller, and it's often necessary, as the subject matter ranges from heavy-duty to soap opera-sudsy. Kutcher is Evan Treborn, a college student who, after growing up suffering childhood blackouts, begins recalling lost memories. The effects are traumatic.

Evan's not just remembering, he's actually zipping back and forth on a twisted time-space continuum, witnessing different versions of his life along multiple timelines. He can now correct past mistakes and easily redirect the paths of friends and family. The idea and execution are usually engaging, but the cheap tricks and clichés are there by the fistful. Kutcher pulls us through the unevenness, though, letting a good chuckle -- and even some unpolished acting -- remind us that this is all in good fun.

What prevents The Butterfly Effect from being a smart early-year surprise is the inexcusably lazy first act. Writer/directors Eric Bress and J. Mackye Gruber (Final Destination 2 scripters) need to start somewhere, and they choose Evan's youth, filled with silly, cookie-cutter dialogue and stultifying acting by both kids and adults (poor Melora Walters). The introduction rushes painfully from scene to scene, yet feels needlessly long in total. Worse, Bress and Gruber rely on psychotic parents and abused kids to get their story moving. It's just all too easy, and the direction and story development feel like Amateur Hour.

When the plot gets to the adult Evan, the film settles in and delivers a fairly wild ride. Evan discovers the breadth of his powers -- again, Kutcher's wide-eyed youth is a plus here -- and initiates time travel, made thrilling by a colorful, engaging, rattling series of special effects that never get tiresome. Once Evan reaches back in time, Bress and Gruber reveal certain story elements previously held back from the audience -- and Evan. It's a narrative gimmick that's been done before, but the filmmakers do it with an entertaining pizzazz and intensity. And, of course, as the title hints, once Evan makes particular changes in the past, other unforeseen ones rear their ugly heads in the present.

It's easy to picture an actor like, say, Billy Crudup in this lead role, with the subject matter "aged up" and given more substantial weight. Nonetheless, considering their Final Destination past, Bress and Gruber are ambitious in their attempt to create a "serious" thriller. The violence, while not visually revealing, is fairly shocking. The downturns that occur in characters' lives are usually overdone (Amy Smart's role especially), but they're still affecting. And even though their script relies too often on quick dialogue summaries to keep teen viewers up-to-speed, Bress and Gruber avoid any excessive winking at the audience.

The Ashton Kutcher crowd (and you know who you are) will probably love this film. Kutcher gets to play strong, scruffy, frightened, remorseful, and even romantic; his loyal fans will see The Many Faces of Ashton. While most actors usually work through this range of emotions in the classroom, this guy has enough Hollywood power to give it a try onscreen and get paid. Now who's the goofball?