Many reviewers consider this to be one the best adaptations of a videogame into a film...Well, I have to disagree, mostly because I love all the Resident Evil games, and even when this is much better than things such as "Doom" or "Bloodrayne", it is just doesn´t make any justice to the original games in which this movie is inspired.
This film betrays the original roots of the game, focusing in the action rather than the horror parts (Sure: The games had lots of action, but also had lots of thrills, mistery and subtlety, something that this film completely lacks)
The other problem with this film is the terrible direction of Paul W.S. Anderson, which ruins a great story, turning the whole thing into a huge mess that is barely watchable.
As a movie independent of the games, it is mediocre at best. But as an adaptation it is just terrible, dreadful film.