Anyone who expects the Doom movie to be anywhere near a good film as you would normally define it needs to be smacked. Its Doom. It should have the following:
1.Hell breaks loose, demons, in short wicked baddies
2. Guns, big ones, and definitely the BFG, to enable shooting said baddies
3. Gore, lots of it. Make that lots and lots of it. Make it obscene amounts of it, the more gratuitous the better.
4. A bad@$$ dude who is gonna wade through it all when the $#!* hits the fan. Since its a movie, maybe they should give him some corny one liners.
Lets see, it seems to me it has them all check. The only problem is that the Rock isn't the lone gun marine. I guess it sounds like they did screw up the Hell breaking loose as well. Another virus? They should know better.
The only thing that they could possibly screw this movie up is if they try to make it more than it is. Don't try to come up with and explanation for anything. Just have a guy blowing everything in the movie away. There's a lot of films that try to be something more and end up just being a big action flick with a hero blowing everything away (Schwarzenegger films for instance). Thats all this movie should be, nothing more. Hopefully they realized this and didn't try to mold it into something coherent, as thats not Doom.