Mostly what's missing is a good script or real reason (other than trying to cash in on an existing IP) to make the movie of a videogame in the first place.
Expanding a little:
1 - many games that are made into films are in fact weak rip-offs of films and/or novels in the first place, and therefore make really poor frameworks for a movie
2 - many games, quite naturally, don't have any real narrative or framework to support a film at all, yet that doesn't stop the money men
3 - sad to say, but for the most part game adaptions are being made with low level talent, which is hardly ideal
4 - most of the time the videogame adaption is releasing alongside a market with better films in the same genre, highlighting their weakness
5 - due to the different nature of the two mediums, I'd say trying to keep movie adaptions closer to the games would for the most part be a bad idea
So actually, unless the IP Universe is potentially strong enough, I'd take the view we could do without cash in videogame adaptions. If a film must be made, I'd argue it would be better to discard the game narrative / plot as it will almost certainly be weak, use the game Universe as the setting and start from scratch with a decent scriptwriter.
In the end I say choose the medium that best suits the material. If you're making a game make a great game but don't bend it into a weak film. If you want to make a great film do so, don't try and make a videogame.
Try to be reasonable... its easier than you think...
