No one was quite sure what to expect in 2007 when notorious wildcard director Tim Burton first signed on to helm a big-screen adaptation of the cult-classic '60s vampire TV series Dark Shadows, a straightfaced soap opera. Intrigue grew when Johnny Depp was cast to play fan favorite Barnabas Collins, an 18th century vampire who wakes up in the 20th century, and Helena Bonham-Carter, Michelle Pfeiffer, and child star Chloe Moretz all booked supporting roles. Now, five years after the project was first announced, the first trailer for Dark Shadows (coming May 11) has been released, revealing that Burton's transformed the sober series into a "very campy" comedy set in the '70s — a move that "surprised quite a few fans". (Watch the video below.) Here are five thing critics are buzzing about:

1. It's a comedy?
"I was expecting a straight-up bloody vampire tale," says Whitney Matheson at USA Today. "What I got was a retro soundtrack and jokes involving disco balls." The Dark Shadows TV show has some pretty passionate fans who might not take kindly to Burton playing fast-and-loose with its tone. Nonetheless, just try not to guffaw when Johnny Depp, spooked by the image of Karen Carpenter singing on the family TV set, shouts, "Reveal yourself, tiny songstress!" Please, says The Boston Herald, the cheap jokes make this look like "Austin Powers with fangs." Tim Burton, "what have you done?"

2. The '70s setting
The film's premise is that, back in the 19th century, Depp's Victorian vampire, Baranabas, spurned the advances of a witch (Eva Green), who vengefully buried him alive. When his coffin is dug up in 1972, he emerges just in time to confront lava lamps. "Judging by the disco-era ephemera on display" in the trailer, says Natalie Finn at E! Online. "Burton's going to milk the notorious tackiness of the decade for all it's worth." The soundtrack's inclusion of Curtis Mayfield's "Superfly" and Barry White's "You're the First, My Last and Everything" certainly help to set the mood.

3. The starting-to-get-monotonous Depp-Burton collaboration
It's been 22 years since Johnny Depp and Tim Burton first collaborated on Edward Scissorhands, and Dark Shadows marks their eighth project together. With a character that, yet again, has  "pale skin, black hair, [and] dark circles under the eyes," this latest Depp-Burton creation couldn't look more familiar, says Matt McDaniel at Yahoo. But that may not be a bad thing. The duo's best work features the same hallmarks — "dark gothic style, extreme characters, and a dash (or more) of zany humor." At the very least, says The HD Room, the two seem to be having fun.

4. The unusual romance
Those craving a serious take on Barnabas' torrid romance with Green's witch, Angelique, may be disappointed to see that Burton's film appears to treat it farcically, says Anthony Breznican at Entertainment Weekly. Still, I'm intrigued by this "comedic, supernatural version of Fatal Attraction" featuring what look to be some uber-campy lovers' quarrels. At one point, Angelique tries to smash Barnabas with a disco ball.

5. Burton's spotty track record with remakes
Burton does better when he puts his own original ideas on screen than when he remakes known properties, as proven by the mixed reviews he received for Planet of the Apes, Alice in Wonderland, and Charlie and the Chocolate Factory, says Michael Arbeiter at Hollywood. You'd think that would spell trouble for Dark Shadows, but relatively few people are aware of the TV series. "To many of us, the idea is original." So while purists may be turned off, Dark Shadows newbies may be more forgiving. Such a radical re-think may actually help the movie attract a larger audience than the existing fanbase, says Sarah Anne Hughes at The Washington Post.