This is the kind of movie that is a lot of fun while you're watching it. Allow yourself to be wowed by the visual candy and go along for the ride. Just try not to think too hard, save that for when the movie is over. Once it's over you can start picking it apart and wondering about certain things.
Resident Evil: Extinction was directed by veteran director Russell Mulcahy. If nothing else, he brings a little experience to the franchise. In that respect, this outing has a bit more focus than the second one. He delivers some fine action and a story that stays on track. The main fault lies with the script, by Paul WS Anderson. My biggest problem is with the ending. No, I won't tell you how it ends, but it feels like a mid-point. Much like Back to the Future 2 ended with the direct lead to the third (which was already filming), this one ends with a lead to a potential fourth film. Not to mention little factoids and plot points that could have done with a little more exploration. You'll know them when you see them.
Even with the lack of depth, this is a movie that provides plenty of action, lovely women laying some waste to the undead, and is flat out fun. I know I had a smile on my face throughout the 96 minutes that it lasted. For the lovers of blood, there are plenty of zombies that get shot up and chopped up. For the lovers of plot, well, I think we already covered that.
Bottom line. Will there be a fourth film? If this one makes some decent bank you can probably bet on it. My guess is that yes, there will be. I have even read rumors of a spin-off featuring the Claire character. Whatever happens, I am sure I will be in the audience. As nonsensical as the stories can be the action is high, as is the fun factor. I am willing to suspend disbelief for Milla. Are you?