Skyfall, the 23rd film in the James Bond series, marks the 50th anniversary of the wildly successful spy franchise, and, judging by the highly stylized, just-released trailer, it also marks a decided shift in tone. (Watch the video below.) Newcomer Sam Mendes directs Daniel Craig as 007, and this first glimpse at his effort "doesn't look all that much like a James Bond film," says Forrest Wickman at Slate. "To my mind, that's a good thing." Skyfall, which hits theaters in November, focuses on an attack on Bond's outfit, MI6, requiring 007 to "track down and destroy the threat, no matter how personal the cost." Here, four things critics are buzzing about: 

1. The genius hiring of Mendes
Drafting Sam Mendes (American Beauty, Revolutionary Road) to helm Skyfall was a bold choice, as the James Bond filmography is unlike any movie he's ever made, says Drew McWeeny at HitFix. But "it looks like that gamble has paid off handsomely." The trailer hints at a "radical departure in aesthetics" from previous Bond films, says Matt Patches at Hollywood. Recent 007 entries caved too much to the "demands and expectations of modern blockbusters" — especially 2008's Quantum of Solace, which "felt like a riff on the Bourne movies." By hiring Mendes, the franchise is "investing in auteurship," which, by the looks of this trailer, could reinvigorate the Bond brand. 

2. The elegant action shots
This aesthetic shift is most evident in the "unexpected visual feast" of action shots, says Patches. There are plenty of big-budget set pieces — like the jaw-dropping footage of a train crashing through a building — but the action scenes also seem integrated into the film in a "dramatic and realistic way." Indeed, the series of "gorgeous and brutal" shots are brilliantly edited for a "hallucinatory first glimpse" at Skyfall, says McWeeny.

3. The mysterious plot
The trailer launches with Bond participating in a word association exercise: "Country? England. Gun? Shot… Murder? Employment." When the interviewer bring's up the film's title, "Skyfall," Bond ominously hesitates, says Mark Harrison at Den of Geek, hinting that he may know something that he's not telling his bosses. Details are scant, but maybe "Skyfall is the codename for the attack against MI6 and its agents."

4. Daniel Craig's winning performance
Craig's "weary-looking shoulders" wear Mendes' genre shift well, says Wickman. Craig has always crafted a "moodier, more psychological" Bond than his predecessors, and Mendes appears to capitalize on that with Skyfall's dark mood. And the trailer's money line? Craig: "Some men are coming to kill us. We're going to kill them first." We can't wait.