I think I already knew this in some degree, but I guess it took a while to internalize: Not to be outdone by DVD's primitive menu system, Blu-Ray lets you use Java: https://en.wikipedia.org/wiki/BD-J
@impiaaa I've thought about running the game* DVD that came with my Tomb Raider movie one (it just lets you watch someone play a custom level with branching paths and some commercials and documentary clips throughout) but it didn't work in VLC
*there's a bonus DVD too but this one also contains the Tomb Raider 5 game, y'know, as a treat
@impiaaa speaking of Tomb Raider apparently the entirety of Angel of Darkness was available as a DVD game which is just wild to me