Colosso, I'm glad I could help a little.
I admittedly belong to those that have never played your other games, and frankly speaking, you should not expect that others are familiar with your previos games. If you want that, the "regular" way would be a series of games in the same manner, i.e., they should all be made in GG.
I am not the most avid gamer of them all, but I am not aware that there are many games that strictly and thoroughly rely on the gamers' intimacy with previous instances of the series. When you think of the "Gothic" Fantasy Game series, you can start with any of its games and even go back to a previous member of the series and still have LOTS of fun, with very few giveaways from a higher instance against a lower.
Maybe, there is no need for many videos. If you should happen to know about the Call of Cthulhu RPGs: they are relying heavily on background, and this is never done by videos, but by carefully designed printed handouts, often in the form of photos, fake handwritten letters, scribblings on anything, excerpts from books, newspapers and magazines, and so on; so, in a computer game, they can easily and economically be presented as pictures.
Lives of great men all remind us we may make our lives sublime