Oliver Stone’s “Alexander” is a narcissistic, emotional, expensive, mammoth failure. And it is well worth seeing because of it.

One of the few directors working in Hollywood today who has complete control over what is released to the public (known as the “final cut”), Oliver Stone is solely responsible for what he puts out. Thus, when things quickly begin to go awry, the director’s struggle, in all its frustrating detail, is splashed across the screen. As an intimate look at an artistic nervous breakdown, “Alexander” is fascinating.

The film follows the typical “misunderstood superstar” arc. Alexander (Colin Farrell) is born to the wily and hot Barbarian-witch Olympias (Angelina Jolie) who raises him to hate his illegitimate father Philip, the king of Macedonia (Val Kilmer). As he grows up, Alexander becomes friends with his dad but is ruled and violated by his mother. At the same time, he falls in love with a male schoolmate, Hephaistion (Jared Leto).

He succeeds his father as king of Macedonia and immediately invades Persia, taking Babylon. Disgusted with his mother, Alexander keeps moving further away from her until he reaches India.

As the Macedonians march farther southeast, Alexander’s hair gets longer — and, of course, obscene hair growth spells trouble. Lo and behold, Hephaistion is ignored, and debauchery ensues. By the time their general’s hair flows down like an ’80s glam-rock star, his army has had enough: They demand to go home, and Alexander’s great campaign ends.

The film’s acting, overall, is sub-B-movie weak. Farrell looks bewildered, never mustering anything near the godlike presence the film so frequently attributes to the Greek hero. As usual, Jolie has to do something ridiculous and demeaning — at one point wearing a snake around her neck while getting raped — and, as usual, she rides with the punches. Her casting as Alexander’s mother initially seems strange, until it becomes clear that her youthful beauty makes the film’s incestuous overtones sexy to mainstream audiences. In fact, all of the female characters seem to have been cast on looks alone, and Stone treats them badly.

The film half-heartedly portrays Hephaistion and Alexander’s gay relationship, showing only enough to tick-off the conservative viewer without really treating their love as viable. Taking the film decisively in either direction would have been fine; but as it stands, the lukewarm relationship is a lose-lose compromise, and the film suffers for it.

The little that can be said in the film’s defense is that it begins well, with decisive storytelling and camera angles. But “Alexander” very quickly becomes scattered and mediocre. The writing is little more than self-contained, glib tag lines masquerading as dialogue. Each character says one clever thing after another, which never approaches anything like conversation material. By the time he reaches the fight scenes, Stone even goes so far as to rip off the jittery camera tricks of television’s “Xena” — never a good sign.

While there are many other serious stylistic blunders — an entire sequence in ketchup-red encompasses several — there are a few startlingly beautiful surprises. A battle seen from the point-of-view of a hawk is especially interesting.

But as a whole, the film is remarkably dumbed-down, frequently repeating visually what has already been said in speech.

At the same moment that Alexander recognizes that he has imitated Oedipus, figuratively killing his father and marrying his mother, Stone seems to grasp that he can’t manage anything original either. With this crippling realization, he regresses in style, resorting to pale mockeries of his past work.

The especially terrible final hour of “Alexander” putters into an assassination conspiracy straight out of 1991’s “JFK.”

The film’s last battle scenes, which emulate the football games from 1999’s “Any Given Sunday,” are the final nail in the coffin of self-plagiarism.

The central image of the film is a cave covered with primal wall paintings depicting the “Oedipus” cycle, Hercules, Prometheus’s torture by Zeus and other myths. The ever-great Alexander is tormented by these archetypes, wanting to emulate them yet do something greater. It is no stretch to imagine Stone in exactly the same position, alluding to “Citizen Kane” with the first shot of the film yet also striving to create something original. Both fail in their endeavors — Alexander a little more colossally than Stone — but both teach us something about failure in the process.