This topic has turned stale now, but for the record I'm about to add a shelf's worth of DVD games to the database. Even though they are on the fringe, I feel that they fit enough of the criteria to be considered video games.
I don't feel that a game like Scene-it would count as a video game. Neither would a VHS/DVD game like Atmosfear. Just displaying video clips, even if the clips or questions are randomized, isn't enough for me to justify it as a video game.
Games that actually use the DVD player as a source of actual game play, score keeping, or other interactive elements should count. When I'm done there may be enough to create a separate DVD category.
Lastly, I am not sure I would count interactive movies as video games. It's a tough call. I don't really see them as 'games' wherein you are trying to achieve a specific goal. But since there are already some listed in the database, I am going to add more.
Any further feedback is welcome!