Film critics will soon argue that Francis Lawrence’s “Constantine” has achieved a level of cinematic integrity that shatters modern definitions of what art means to man. Keanu Reeves graces the screen with the elegance and acuity of a young Lawrence Olivier. Prospective viewers beware: This film — nay, masterpiece? — will sculpt new societal paradigms while razing notions of religion as a cultural currency.

But, alas, I’m kidding.

Perhaps the most miraculous feature of “Constantine” is Keanu Reaves’ noticeable abstinence from muttering the word whoa. Other than that paltry feat, “Constantine” has the dubious achievement of providing entertainment akin to a long sitting of a mediocre video game. After two hours of shrieking demons, wooden acting and amazingly stale one-liners, you realize that a power-hour of Xbox would be a much more cost effective use of time.

It is all too easy, and nearly unfair, to pan this movie so maliciously. While hard to allocate merit to a film that shamelessly extols the cinematic styles of such miserable CGI epics as “The Mummy,” it deserves scanty respect for its relentless visual spectacles. But any attempt to praise the latest reincarnation of a Keanu-in-a-black-suit action flick is in vain; it’s still a thoroughly bad film.

Lawrence’s opus of awkwardness appropriately begins with a cryptic and laughably dumb opening screen of text: “He who holds the Spear of Destiny has the fate of the world in his hands. The spear has been missing since WWII.” However, lucky for the impatient moviegoer, the spear is discovered in the first two minutes of the film. Across the border, an impoverished Mexican finds it buried, snuggly swaddled in a Nazi flag. After a new set of menacing contact lenses, he becomes the sword’s robotic guardian. His mere presence can slaughter an entire field of cows (though this isn’t worth being confused over).

After a knock-off “Indiana Jones” introductory sequence, the film cuts to a tightly zoomed frame of a cigarette slowly plummeting to pavement. Enter John Constantine, Earth’s favorite chain-smoking demon slayer, armed with the acerbic bitchiness of a news anchor off camera. Self-consciously arty cinematography introduces the film’s flawed protagonist, as he approaches the bedroom of a demonic teenage girl. “This is Constantine,” a corpulent middle-aged man awkwardly injects. After his bizarre introduction, Constantine whispers religious prattle over the hissing girl before trapping her writhing demon into a mirror and throwing it out the window. All in a day’s work.

Based on the DC/Vertigo comic book action hero, Constantine leads a tragic life — after his adolescent petulance went awry (he committed suicide), he’s now a policeman for Earth’s population of roving demons. The job description includes living in a conventionally drab apartment and frequenting lame bars with Eurotrash techno and too much vinyl apparel. Unfortunately for John, his terminal lung cancer will transport him from one depraved society (LA) to another (Hell.) His only hope at reaching Heaven’s pearly gates is paying off his spiritual loans by killing poorly behaved half-breeds — demonic quasi-humans with deleterious influences on their surroundings.

If it weren’t for the stunning and surprisingly talented Rachel Weisz, “Constantine” would suffer a much crueler fate. A veritable goddess of putrid CGI cinema, Weisz (of “Mummy” fame) stars as Angela Dodson, a detective distraught over her twin sister’s impetuous suicide. Like Constantine, Angela can see hidden truths, in the form of conspicuously fake demons. But not even Weisz’s refreshingly good acting skills can mask the odor of the “B-movie” stench.

The movie itself is a battle of good and evil. On the one hand, the biblical fantasy aspect provides rare plot twists (Hell has its own Bible? Lucifer has a baby?), and the casting is sporadically superb. Tilda Swinton takes a terrific turn as an androgynous Archangel Gabriel, Peter Stromare achieves a dazzling creepiness with his rendition of Satan and even Los Angeles, swathed in inky darkness, looks ominous and splendidly noir.

But the movie is certainly rife with its own set of evils. For one, the screenplay is excruciatingly stupid (“You’re my appreciated apprentice, like Tonto or Robin,” John straightforwardly says to his plucky sidekick Shia LaBeouf). Worse, most of the computer animation is exquisitely bad. Lawrence’s warbly, demon-infested Hell is more visually incredulous than most Playstation games. Yet these glaringly dreadful flaws don’t deter the film’s potential to entertain, which is hard to deny.

Will you enjoy two hours of Keanu’s stale acting in comically lame environments? While it may not elicit a “whoa,” you very well just might. Just pray to God that there won’t be two sequels.