There are already some huge maps out there, Just Cause 2 and 3 both have maps at around 1000km2, and those games are beloved by their players. But if the next Cyberpunk game was announced with Night City now being the size of an actual large metropolis, say like New York, would you say that’s too big? What determines what “too big” is?
It is too big when the density of reasons to go there and explore becomes to little.
Personally, I don’t really care for games that have huge maps just to pass through while traveling around. There needs to be a reason in the story for every place to be there.
Every village, town or city needs to be filled with quests and stories, and the space between them as well to a lesser extend. They serve as immersive distractions. They need to be alive.
The map is too big if it cannot be filled with enough stuff to explore and experience. And I don’t mean climbing yet another tower, or doing yet another variation of the same puzzle.
TBH, I am not much of a sandbox game player and the JC 2 and 3 maps looked nice, but didn’t really invite me to stay and explore a single area for a while, because the areas didn’t have much depth. I prefer a much higher density of things to do. Each village should have a couple of hours of content, exploring it and the neighboring area. And larger towns or cities even more.
I want to minimize the ‘just cruising through’ parts of maps.
Cyberpunk as well had too much dead space when it comes to stuff to do in many parts of the city. Some parts of course act as just the background for other parts, which is fine. But other parts where beautifully handcrafted and interesting, but there is not much to interact with or people to talk to there.
To me it is important to have enough content and depth that the player learns to get to know their way around a place, and gets to know characters and develop relationship with each place.