First of all, this is not an oscar-bound movie, so don't expect it to be anything it's not.  It's an excellent horror/sci fi thriller that kept me at the edge of my seat from start to finish.  Just turn off your brain and let the zombies munch on it for awhile and have some fun.  Don't think too hard about plot holes and such :-)  Resident Evil is truly frightening, and is one of the few movies that actually made my heart pound in fearful anticipation.  The movie is excellent at creating a kind of clausterphobic panic that really gets to the audience.  And yes, there are more zombies than you can shake a stick at.  And just when you thought there couldn't be any more zombies...