Sci/fi horror stories. You really don't expect such charatcer development in these types of movies, but this one does an excellent job, from start to finish. This is definitely not a B movie, not by a long shot.
You find out for example that the bad guy is not always the bad guy. In the crash sequence after all the dust settles and Johns finds an empty cryo sleep tube and his gun missing, it's found on the floor under a dangling Riddick. Now if Riddick was such a bloodthirsty bad guy, he would have taken the gun and shot Johns and been done with it. This is the second interesting development in the film, and gives you a nice window into the character of Riddick.
The first interesting development is the moral dilemna during the landing/crash of the ship, in which Fry tries to eject all the passengers.
The third interesting development is the assuming of Riddick's guilt in the death of Zeke, for which no one has apologized yet.
I've rarely seen such a depth in chracters in the scifi genre. All of the characters go through some deep changes under the pressure of the struggle to survive. Check out the expressions on the faces of the actors, and the dialogue, excellent job, without overacting or forcing.
The special effects are good, and they don't overwhelm the story. The plot is good, and the suspense stays with you up until the very end, building and ebbing throughout the film.
I wish they'd have had a bigger budget for this one, but if they had they'd have probably overloaded on the special effects.
Overall, I would give this an excellent rating as a movie buff.