Look, the movie wouldn't get 4 stars under most conditions--but these are NOT most conditions. The movie is based on a video game. It had a real theatrical attempt in 2005. Watching it ought to be like gouging your eyes out with forks.
Watching it is NOT like gouging your eyes out with forks. It's a solid B-movie type monsters-vs-space marines flick with okay dialog and plotting and it doesn't make any horrible mistakes (such as totally getting military operations wrong or having the characters not be semi-believable soldiers. They aren't believable "special forces"--but they work fine as regular enlisted).
The effects aren't great--but they're fine. Mostly practical inside the base which is actually refreshing. The main character does a good job of selling herself as a leader who feels she screwed up her men. I mean, it's not a great film--but it ought to be horrible and it's actually a decent ride.