It's pointless to give it a 10, that won't increase the rating on imdb as much as you think. They aren't doing a plain average calculation, it's a formula designed to counter these fanboi/hater actions. It's nothing unusual that the rating on imdb is much higher than rotten tomatoes, because critics are kinda retarded and their way of calculating the outcome is shit. Movies like this have a target audience and critics are not really in that category. Plus they have to keep up the myth "all videogame movies are shit"