To answer my co-blogger's question, I saw Chronicles of Riddick on the weekend. Verdict: 7 out of 10. Imagine, say, if Stargate (the 1995 movie) had been filmed by Tim Burton, and you've got the general idea. Like Stargate itself, not awful, in many areas quite intriguing and thought-provoking, but could overall have been done better. Also bits of Starship Troopers, Judge Dredd and, indeed, most of the other not-awful-but-also-sub-LotR/ Gladiator level science fiction/ fantasy/ sword-n-sandals stuff served up over the past 12 years (ie, since film spec-fi reached its absolute nadir in 1992 [*])... And also very large chunks of Alien-3 (and Alien Resurrection). Not surprising, seeing as David Twohy scripted both. Stephen King once told an interviewer that, if he were a "serious" author, the critics would rave that "King is now re-visiting themes that are integral to his work". But since he was Stephen King, all they'd write was "King is starting to eat himself".
The most interesting element (excuse pun) of Riddick is its bad guys -- a Nazified warrior death-cult called the Necromongers, who sweep across the galaxy on a jihad crusade to convert or kill entire worlds' populations. These guys are about six-tenths the Borg, three-tenths the Harkonnens and/or the Sardaukar from David Lynch's 1984 "Hmm, melange pie" version of Dune, and the remaining one-tenth the aliens from Dark City.
The least interesting element of Riddick is what the producers, and I assume Vin Diesel (the film's star and driving force), seem to have considered the most interesting: the punch-ups and knife-fights. They go to the trouble of postulating an intriguing future interstellar civilisation, and an intriguing bunch of enemies whose alien religion and eldritch powers threaten it... but they don't pay it too much attention. In the end, Riddick wins because simply he's a tougher, meaner, head-kicking badass than even these death-cult super-Sardaukars who're in his way. He wins, basically, by dragging himself across a sun-scorched rockscape and by killing someone in a knife fight. He doesn't win by turning his enemies' powers and strengths against them [**]. The Necromongers might as well be Cylon Centurions or Spielbergian Nazis for all the difference they make to the plot.
Oh, and don't put too much stock in what mainstream film reviewers write about science fiction/ fantasy movies. I don't think I've ever seen one get a positive review from David Stratton or Evan Whitton (other than LotR of course). What the fans find interesting -- bizarre new ideas and exciting plots -- is a turn-off to mainstream reviewers who are more interested in the exploration of character (read: neurotic teenager lies on bed watching fan rotate for 25 minutes).
As Isaac Asimov once noted, SF can't afford to focus too much on character because that would detract from the changed world in the background: "Gulliver is an ordinary man and Alice is an ordinary girl. To have strange people in strange worlds would be one strangeness too many".
That's not to deny that written SF would benefit greatly from losing some of the pulpy cliches ("The twin suns rose early that morning. They shone hotly upon the towers of the planet of Cesarion Prime, which had just been conquered by the Zargvorod Imperion. Faulchok watched the suns rise with barely concealed anger in his three eyes. He hated the Zargvorods because they had killed his father three years before...") so beloved by its more successful practitioners. But as writers as diverse as CS Lewis and Philip Pullman have shown (now there's two names I never thought I'd use in the same list), it's entirely possible to competently depict the characters in the foreground while focusing primarily on the big vistas of the universe in the background.
[*] 1992: Freejack. The Lawnmower Man. Highlander II: The Quickening. And Alien 3. The prosecution rests.
[**] Unlike, say, the much-maligned Last Trek, Nemesis, where (warning: spoilers) it was Shinzon's earlier use of his telepathic powers to mind-peep on Deanna Troi that later allows Picard to locate and strike his cloaked starship.
