Adventure games are a beautiful and archaic mess.

Other games tend to offer a challenge using the four stages of competence. Players learn the mechanics, get punished, rewarded, run up to the limits of their abilities, (preferably) get better. Try again, embrace the learning curve, improve your results. Like playing an instrument or driving a car. But that's also a limitation. Because you can't do certain mental challenges while playing an instrument or driving a car. The type of mental challenges a demon would come up with to torment you.

This is where adventure games come in.

At this point, the term has become so generic that it has lost its meaning.

I guess it's a game in which you have an adventure, but it's not an RPG, arcade, or simulation game, though it can have elements from RPG, shooter, or simulation genres.

In the past, I've tried to come up with a robust definition. Something like, an adventure game's core gameplay focuses on exploration, dialog, and using ordinary objects to solve puzzles. "Ordinary" being relative to the world of the game. I think I was trying to figure out a clean way of excluding shooters. In other words, if you primarily solve your problems with a weapon, that isn't an adventure.

I think that works well enough. But in practice, I go on vibes. How similar does this new game feel compared to other games that are firmly, obviously adventure games?

Portal, to me, is an excellent game, but not an adventure game. When I play it, it just doesn't feel like playing an adventure game. I'd describe it as a puzzle-platformer. But I don't really care what you call it, it's fun, regardless.