I saw Riddick last Friday. I am a fan of the series. It is really sort of like Conan in space. Definitely a dark space opera, but fun. The new film follows many similar beats to Pitch Black, but it is not a carbon copy. It actually brings the feel of the first two films better and makes them seem more cohesive. You get to see Katie Sackoff's breasts too so hey, that's a perk.;)
Most of the effects are okay to good. The creatures came out pretty well. There is only one scene where three characters ride something like a speeder bike or swoop from Star Wars in the daytime to track Riddick where the CGI was not up to par, but considering the lower budget and sacrifices made to finish the film, they did a better than okay job.
It is not going to knock your socks off, but it won't make you hate it unless you hate the series in general. Then nothing I can write would change that.
You know I am not into the fast & furious movies, but to get Diesel to return to that film series for a cameo in Tokyo Drift, Diesel made a deal where instead of getting paid, Universal gave him the rights to the Riddick franchise. So that is how the movie got made.
He even put up his house at one point until the bank bond came through. So unlike those f&f flicks, there won't be a new Riddick film coming soon. It might be a few more years, but Diesel and Twohy are committed to completing their story for the character and since I respect that they are trying to do something a little different and bring a vision to completion, I hope they succeed. I think I might even donate money if they did a kickstart for it.