Other watchable "Video Game" Movies:
- Final Fantasy VII: Advent Children:
...it's a sequel to a video game, so yeah. The Story might be paper thin, but is tolerable, especially since the movie itself is an absolute audiovisual blast with great over-the-over-the-top-action. And i don't even like the game!
- Futurama: Benders Game
...okay, that one's about Pen and Paper RPGs more than anything. But most of the jokes definitely apply to videogames too.
- Crank
Come On! It doesn't even hide it! It might not be based on a Game, but it's story combines a premise of an arcade game on acid with the stupid, senseless fun of an open world action game like GTA and Saint's Row. And no movie captured this like that.