In the recent Math Blaster submission somebody
presented the suggestion that rather than define which
genres of games are acceptable and which aren't, instead it could be better to define the characteristics that a game needs to have, in order to be acceptable for TASing (and publication here).
This reminded me of how I once purchased a visual novel on Steam, thinking that it would be an actual video game ("adventure game" as they are called in Japan), and getting disappointed because it was indeed a pure visual novel with no gameplay elements of any kind. I wrote a negative review of the game, main argument being that it actually wasn't a game at all, even though it was being sold as one.
I ruminated on what exactly makes a video game an actual video game, as contrasted to just a pure visual novel (that consists of nothing more than pictures and paragraphs of text, with no interactivity). I came up with these minimum requirements for an actual video game:
Firstly, interaction: The program must be interactive in some manner. And this interaction should go a bit further than to simply wait for the user to click to advance to the next paragraph of text.
This is tightly tied to the second feature: Choice. The player needs to be given some kind of choices, no matter how primitive, rather than the events on the screen happening in the same manner completely regardless of what the player does. This could be, for example, choice of direction of movement, or choice of dialogue. Even if these choices have no grand-scale consequences to speak of, the mechanic should still be there.
Thirdly, a goal: A game should have some kind of goal that the player strives toward. It's not a question of how complicated or large that goal is (it could be extremely primitive and simplistic), but there should nevertheless be something that the player is trying to achieve, which is the point of the game. (This doesn't mean that the game must have an ending. A game could very well be endless, such as trying to play for as long as possible, with progressively increasing difficulty. The goal in this case could be, for example, trying to achieve the highest possible score.)
Fourthly, challenge: Achieving said goal should not be completely and absolutely trivial. This ties to everything above: Achieving the final goal ought to involve player choices, and those choices should be even slightly challenging. It should be something more complex than simply "click to advance". (This doesn't mean that the game has to necessarily be difficult and require great skill or knowledge. Even a very easy game can still be fully considered a game.)
Of course these characteristics are just something that define a video game, not something that defines a "TASable" video game, but perhaps something like this could be concocted for a definition?