I went into the movie expecting and wanting to like it. But I came out of the movie . . . disappointed.
Let's see if I understand the movie:
Necromunders are attacking and capturing/destroying all the planets of the universe. There are many hints that Necromunders are some kind of undead, but nothing is ever actually explained.
Humanity needs Riddick to stop the Necromunders. So the holyman and elemental put a bounty on Riddick to get mercenaries to hunt him down. Riddick fights off mercenaries and takes their ship to the holyman.
While with the holyman, the police show up. Why did the police want Riddick? For the knocking down of the "interceptor"? How did they know where to look for Riddick? Was the fight scene cool or exciting? Don't know, because it was all dark or strobed.
The Necromunders attack and land that very night. Riddick fights a few, then goes to the "town hall". A Necromunder soldier is not killed (or apparently even bothered) by a knife sticking out of his back, but he is killed when Riddick sticks that same knife in his gut. Huh?
Riddick surrenders to the Necromunders. The Necromunder woman explains to Riddick how they alter people to become Necromunders, and then Riddick allows them to put him in some kind of chamber. Why? It looked like he was willingly laying his head on the chopping block. And he got nothing at all out of that whole episode. He manages to escape the Necromunders.
The mercenaries catch up to him, and he again willingly surrenders to his (other) enemy. So the mercenaries take him to the prison planet of Crematorium. Riddick wanted to go there to find Kira/Jack.
At the prison planet, while the mercanaries haggle for his bounty, Riddick escapes his bonds. If Riddick is so damn bad, having so many and so high bounties on his head (the merc can choose who to deliver him too for the best reward), why don't they just put a bullet in his head and be done with his killing and escaping?
The whole prison system of Crematorium is non-sensical.
What was the bond or understanding that Riddick had with the dogs? That was never explained.
How was the mercs v. guards fight "planned" by Riddick?
The escaped prisoners were outrunning the sunrise? Over that terrain? And when the sunrise finally caught up to them, at the wall, they managed to outdistance it again, with enough time to spare to sit down and watch the Necromunders land and fight the guards.
Riddick, Kyra, and the prisoners fight the Necromunders. Was this scene cool and fun? Don't know again, because it was all close up shots of Riddick, and what was panned back enough to see the actual fight was so jumpy and blurred as to make seeing details impossible.
The Necromunders leave, thinking Riddick dead. The Commissar Necromunder pulls Riddick to safety in the landing pad as the sun rises (again). The Commissar Furian/Necromunder explains the situation to Riddick then suicides by walking out into the sun light. Why? Why suicide? And how does Riddick survive the sunrise just because he is in the hanger, just 10' away from 700 degrees? Good thing for Riddick that heat doesn't spread in his universe.
Riddick flies back to the Necromunders and infiltrates the main ship (we don't see this done). Pretty quickly, Riddick is in personal combat with the Lord Marshal. The LM dies. Riddick is given the throne of a force he doesn't want, leading a religion he doesn't beleive in.
So, what exactly were the Necromunders? Where they undead? If so how could they die from knives and beatings? What were the strange heat-seeing Necromunders? If their purpose was to spot living creatures (as opposed to Necromunders), this suggests the Necromunders were indeed undead. But, again, how do they die from standard wounds? What use being undead?
What are the elementals? Why was this race even mentioned? The one member we saw was nothing but a "wise woman". Why was it necessary for her to not be a regular human?
Riddick was very willing to allow himself to be captured and put into potentially suicidal situations just so he can act all cool by claiming to have orchestrated everything that happened.
There were sooooo many major things in this movie (universe) that never got explained. And I hate it when movies take a plot/story that could/should very well take many movies to tell, and reduces it down to 2 hours. Hell, Riddick spent more time in the irrelevant (to the plot) prison planet than he did against the Necromunders, which the whole movie premise was about.
The more I think about this movie, the more I dislike it. The day after seeing it, I just felt like it was neither good nor bad, just there. Wouldn't recommend it, but wouldn't deride it either.
Quasqueton