I think the comics are even earlier, or at least tell the story on the planet. Anyway I just watched it. If you bought into the Dead Space universe (like I did), and you can stomach a load of horrifically cheesy one-liners from the cardboard thin cast (especially the main character), then go ahead and watch/buy. It's interesting to see how the incident came to happen exactlty, and its cool to see a few scenes that were in Isaac's video and audio logs actually played out. There's a lot of "laugh at" gore, but nothing scary, the film doesn't even have any real jumps.
Something's up with the creators though, there's a scene in a shower with a naked fat man being chased by the necromorphs, you see his schlong and everything... its not nice.