What we’re talking about here is very related to a debate that was happening in game studies in the late 90s early 00s, namely ludology versus narratology.
To put it simply, narratologists were using tools from other disciplines such as cinema and literature to analyze games, they fundamentally treated games as a narrative. The ludologists said games are fundamentally defined by rules, mechanics and play. And that treating games as a narrative is at best not doing them justice and at worse, misleading.
The debate has simmered down, and it’s widely accepted that it’s more fruitful to analyze how these two aspects interact, and I’m largely in agreement.
So I’m personally not interested in “pure games“ per say, BUT I do think it’s interesting and useful to observe how games differ to other mediums.
Here, I think you are really onto something @adriendittrick in regards to secrets. I believe a core aspect of video games is their inherent lack of transparency. With a board game, all the players know the rules and collectively act as the engine processing those rules. Likewise, with physical books there is no mystery to how it functions as an object, despite how mysterious or confusing the literal text might be.
The inner workings of games are hidden to anyone who doesn’t have the source code. Even games that make those calculations clear to us can be subverted, I think I recall an old Civilisation game purposefully giving false percentages to the players.
I believe this a major aspect that makes games so compelling, playing them, figuring them out, has similarities to living in the real world. Newton’s laws have proven useful through hundreds of years of practical and theoretical science, but the world is still a black box to us. Even if we did have access to the source code of a game, it can still break and behave in ways we never expected.
Note: I also wanted to weigh in on interactivity in general. For me this metric isn’t very helpful, I think all mediums are interactive by definition. We flip pages of a book, we pause the movie, we dance to music, we look at a painting. I understand games require “more of us”, but only in a very specific way. I don’t see how that fundamentally differs from book of dense philosophy or an art house film with unconventional story telling.