At the end of the day I think therein lies the difficulty. The entire point of a movie based on a video game in my opinion would be to allow fans to explore the world further in another medium. It's to enhance immersion, not replace it. A great video game movie probably wouldn't be very good for someone who hasn't played the game.

I think a good example of this is the Warcraft movie. Pretty terrible reception overall. But as a Warcraft fan I really enjoyed it and would love another.