Yes, Tron is an interesting choice because it created a universe that sucks you in - like if you were playing a video game while watching the film.
House was the first film where I had no influence on the script. I had to buy the script with the game rights.
So if you want to have a great video game-based movie you have to keep the mood of the game, use the normal character setup - but you have to flesh out the story and provide more background for the characters.
My favourite game is Postal because it is so politically incorrect.
I think video games are a great kind of entertainment. They have replaced a lot of games people normally play with their friends and neighbours, like Monopoly.
Take the hardcore gamers. The characters are way more real in the world of hardcore gamers who have played the game for hundreds of hours. They have the movie in their heads, they've built it on their own. These guys are always very disappointed in the movies.