Contains spoilers
I used to have a lot of time for Richard B Riddick, the gravel-voiced killer convict.
Back in 2000, Pitch Black was the surprise low-budget sci-fi thriller of the year. Nicely scripted and directed by David Twohy, it gave Vin Diesel his breakout role as RBR.
Taut, creepy, and surprisingly enjoyable, the thought of a follow-up was a tantalising prospect.
However, by 2004's The Chronicles of Riddick, it seemed too much money had been spent on special effects, mammoth sets, and gothic costumes, and not enough on Twohy's muddled script.
Despite an excellent set piece, in which the eponymous hero and his colleagues attempted to out run the lethal sunrise on a prison planet, and Judi Dench as a diaphanous alien, TCOR was a mess.
However, at least the video game was a lot of fun.
So when it was announced director and star would be re-teaming for a third chapter, I hoped it could redress the balance.
Sadly, Riddick - the movie - is a massive let down.
Despite being the ruler of an army of fearsome Necromongers (life-sapping alien bad guys from film two - who must have had a hand in the life-sapping editing), somehow Riddick is conned into leaving his empire for what is supposed to be his home world... but isn't.
Like a moist calculator, none of this adds up.
Despite his survival instincts, he thinks standing on the edge of a cliff face, like Wile E Coyote, is a good idea.
Imagine his surprise when the bad guys turn on him and one shoots the ledge so it collapses, and takes him with it.
Duh.
The first third of Riddick drags like a wet bank holiday Monday, or a party political broadcast in bullet time.
Despite being stranded on a planet full of a ravenous dingo-type predators, our hero manages to fend them off, pinches one of the cubs/puppies (reminiscent of Scrappy-Doo in the Scooby-Doo live-action version), and clashes with assorted scorpion-like beasts.
Arriving at a way station with grown dingo, he activates a beacon to call for help. Only Riddick would never call for help. He's far too macho.
Act two sees the arrival of two parties of feuding Mercs, aka bounty hunters, one of who wants Riddick's head in a box, a bit like Albert Finney in Dennis Potter's swansong, Cold Lazarus. Only inanimate.
We know this because he seems to tell us every five minutes, though his accent is so thick, subtitles would have helped.
Then again, they would help with most garbled action films these days.
Most of the Mercs are generic idiots. Twohy's a natural when it comes to creating none-too-bright secondary characters, as he proved with the maddeningly overlong Waterworld in 1995.
However, there is a sub-plot involving the father of a deceased character from Pitch Black, who few fans of the original cared about, and Battlestar's Katee Sackhoff will leave Big Bang Theory followers drooling as a lesbian sniper.
Indirectly, hers is perhaps the most troublesome antagonist, largely because of the shockingly dated, homophobic reactions she causes in assorted characters, including Riddick.
Any sympathy I had for the gruff anti-hero goes out of the window with a couple of horrendous lines of dialogue.
And by the time she descends from the heavens, angel-like to rescue Riddick from swarms of lethal predators, part of me wished she'd left him to die.
Not since James Bond managed to turn Pussy Galore 50 years ago has a heroine of sorts had such a dramatic change of sexual preference.
Clearly the sight of Riddick on a rock also made her realise that sexist, murderous ex-cons are everything she's been lacking in her life - when she's not shooting their dog that is.
Made for less than $40million, Riddick is a masterpiece of economy, no doubt helped by the Star Trek TV-style sets and judicious use of Universal's props warehouse, which I was lucky enough to wander around last year.
(I'm guessing there's a few left over costumes and gizmos from TCOR and Serenity dusted down.)
Alas, some of the special effects are shockingly bad, especially during the hover bike scenes.
When are film-makers going to learn that hover bikes in fantasy movies look rubbish? See Judge Dredd and the Star Wars prequels for further proof.
Aesthetically they just look like a kid's toy bike with the wheels pulled off.
If you've been weaned on adult fantasy comics, such as Heavy Metal and Marvel's epic Illustrated, chances are you yearn to see good stories well told in exotic universes.
Riddick could have mined that rich seam of inspiration to craft something thrilling and inventive. Sadly it's just an overlong, annoying fantasy Western with a cast of mostly unlikeable characters.
Okay, it's not as bad as Diesel's previous sci-fi offering Babylon AD, but it comes close.
Elysium (this year's other hardware-centric sci-fi epic with a bald hero) may not have been perfect, but it was about something other than macho posturing and mundane alien-slaying. Twohy and Diesel could do worse than take notes if Riddick returns.
To sum it up in two words? Chronic and ridiculous.