Even though most of what happens in the movie occurs offscreen and we only see the aftermath, there was an aggressive edge to it. You get the impression that Romero would have shown you everything if he'd been able to make it look effective. But "Night of the Living Dead" combined its early gore effects with a certain level of pseudo realism that was missing from the campy, color grossout films being made by Herschell Gordon Lewis, and an unflinching attitude that went beyond anything that was typical at the time. Ben, the hero, bashes in the heads of several ghouls in the beginning, using a tire iron. At one point, he embeds the sharp end in the skull of a zombie, and it falls back to the carpet after he pulls the tire iron back out. Even though the penetration has occurred off screen, the illusion is very effective. It still looks upsetting today, as does the grossout scene where a group of zombies fight with each other on-screen over a pile of intestines.
Another thing I love is the way Romero was able to make the murder of Helen Cooper so compellingly surreal and brutal at the same time. Her death is the one zombie attack in the film that never fails to freak me out, the nightmarish pinnacle of the film. You know the scene, it's when she goes back into the basement as a last resort and the little girl zombie kills her with a handy cement trowel. When I was a kid I used to always wonder why Helen never tried to defend herself with her hands, but as an adult it becomes a little more clear to me that she's in the moment; she's just seen her husband shot dead in front of her, scores of zombies are beginning to burst through the barricades, and she has now discovered her young daughter is not only dead, she's devouring what's left of her husband. When the little girl advances on her, Helen just kind of collapses in shock and lays there, letting her own little girl slowly hack open her ribcage, an agonizing death, all the while emitting those unearthly death screams as it happens. It's a moment of true horror, a subversion of the family unit in a way that wasn't often seen with such chilling detail. It happens with Barbara, too; of all the zombies that have inexplicably come to this rural farmhouse, the one that confronts Barbara is her own brother, Johnny, who drags her off into a crowd of ghouls to be devoured. Barbara has remained disassociated throughout almost the entire film until that very moment; seeing Johnny seems to bring her out of her shock long enough to realize she's about to be killed, and she screams for Ben to help her, too late. I always shudder at the way you can see her face for a split second right before they pull her all the way down and, presumably, rip her apart while she's still alive. These weren't strangers committing acts of random violence, these were the family members of their victims. Romero & Russo weren't only interested in showing a brutal murder, it was also a total mindfuck.
The cynical, downbeat quality of "Night of the Living Dead" breaks some serious ground for horror, as other filmmakers began to emulate such things as the explicit use of gore, the zombie subject matter itself, or the unapologetically gruesome tone.
Contrary to popular discourse, the movie does indeed offer an explanation of why the dead are returning to life. The talking heads we see on television reporting the phenomenon have made a link to a recently crashed space probe that carried high levels of "mysterious radiation". The film's 1978 sequel, "Dawn of the Dead", completely sidestepped this explanation, and this time Romero stated in interviews that there was no known reason for the reanimation of the dead, and that the radiation scenario from the original was not intended to be the definitive explanation. But Romero had also started referring to the work as a 'trilogy', and that it had always been intended as a trilogy, which is something he had never mentioned in print after the original film debuted...prior to his 1977 interview in Film Comment, he'd never even alluded to a potential sequel. In fact, two years after making the 'trilogy' comment, he told Cinema Spectrum that when he was making "Night", he never knew he would ever make another film like it. It seems odd that in a script like "Night of the Living Dead", the crash of a radioactive space probe and the subsequent emergence of zombies from that same area could have been intended as anything other than an explanation. Otherwise, what the hell was it, a strange coincidence?
Regardless of implicit intentions, the ending of "Night" closes on a scenario where the living now outnumber the living dead once more and are rounding them up to be thrown onto huge bonfires. The TV news reports that the level of the radiation is decreasing, and this is the ultimate tragedy of our small group of non-survivors: if they'd just managed to hold it together a little while longer, they'd have lived to see the end of the emergency. Instead, they're all dead at the end.
The moment any movie's end credits begin is often the moment where people stop paying attention, but that's one of the most disturbing aspects of "Night of the Living Dead". Hidden in plain sight during the end credit sequence is a series of horrifying still images of Ben's body being dragged away by possee members weilding meat hooks, to be thrown on a bonfire with other bodies and set ablaze. Knowing that just moments before, he was the only survivor of the film, and a random act by an overly enthusiastic possee member leads to him being shot dead and viciously violated. This wasn't done to him by zombies, but by ordinary, living human beings, with shotguns and meat hooks. Now that's a scary concept.