I'll be blunt, this sequel was unneeded...

Rating: 6/10 (28 April 2009)

But that doesn't mean it's a horrible movie. It still has it's moments, but it's not as good as Alien and Aliens or even Alien3.
Acting? It's okay... but could have been a lot better. I have to admit that even Sigourney didn't perform as good as she did in the first 3 films, but then again, she is now in a completely different role.
The story is not excellent, nor is it horrible. It's just your standard scenario. There are tons of films who have a story development like this.
The effects on the Aliens have once again improved and the creators really like to show it off. Almost every scene where Aliens lurk, they show on the screen. Sometimes full body, other times just heads or claws. This, in my opinion, is bad. The fact that CGI exists doesn't mean you have to show it every 5 minutes or so. They really over-used it and it damages the quality of the movie.
A few new twists and better effects.
That's basically what Alien: Resurrection adds to the series.
It's a shame that this movie ended the Alien saga. I don't count AvP and AvP2 as real sequels, but rather as a new series.
Watch it if you are an Alien fan and liked the first 3 movies.