Here are a few suggestions for naming these two separate imageboard boards:
For the board focused on discussing videogames as a topic and things around it, you could consider using a name like "Videogame Discussion" or "Videogame Culture" to describe the broader scope of topics that would be discussed.
For the board focused on discussing specific videogames/franchises, you could use the game or franchise name itself, such as "Doom Board" or "Zelda Board", to make it clear what the focus of the board is.
If you'd like to differentiate them further, you could consider adding a tagline or subtitle to each board to more clearly indicate the scope of the board. For example, the videogame culture board could have a tagline like "Discussing the industry, development, and culture of videogames," while the Zelda board could have a subtitle like "All things Zelda, from classic titles to new releases."