Okay, first of all, this movie isn't good. The script is nothing special, the acting is pretty horrid (with the exception of the two leads), the effects are pretty atrocious, the weapons silly and the direction poor.
But hey, it's a Sci-Fi original movie. And a pretty damn good one at that. It must be expected that this film will have plenty of flaws about it just because it is a Sci-Fi channel movie. After all, this is the same studio responsible for Sharknado, Sharktopus, Boa Vs. Python, Lake Placid 2, Lake Placid 3 and more atrocious films. However, they have made decent movies before. Kaw wasn't terrible, The Insatiable was pretty creative and Sabretooth is a guilty pleasure of mine. There have only been a few of these Sci-Fi Channel original movies that have been decent. I mean, they're all so horrid only a few are remotely enjoyable. I think all of these movies were filmed in Bulgaria (which is only famous for producing bad movies), so all of them have bad acting because the actors are foreign and don't know English so their lines had to be dubbed over in post-production. This explains most of the bad acting in this movie. The effects are obviously bad because of the small budget but as bad as they are, trust me, they could have been WAY worse or even CGI, which is as bad as it gets when Sci-Fi gets involved.
The plot of this film is fairly unique, and Bruce Campbell absolutely steals the show. It's certainly fun to watch and even though it is no masterpiece, this film works as a fun way to spend an evening mainly because it doesn't take itself too seriously but also wants to tell an entertaining and enjoyable story. It's worth a watch, or maybe even a few. Like I said, just don't expect a masterpiece like The Godfather or Citizen Kane. For what Alien Apocalypse is, a Sci-Fi Channel original movie, it's not half bad.