We had an interesting query from @zachc over on Twitter. Thought I’d answer here as well for visibility!
In terms of games currently being developed on SpatialOS, the Lazarus map is 400km by 400km for a total game world of 160,000km^2.
As far as I know, the largest contiguous land mass in a game is The Elder Scrolls II: Daggerfall at 161,400km^2. Now, things become tricky when you start looking at games like Eve Online and how to measure geographic distance there. That being said, you could well create a physical map larger than that of Lazarus on SpatialOS. The question then would be whether it’s worth doing so and how it benefits players.