In the update before last, I added a world setting to the game - a seed, so, in fact, this is not a seed :D no, it works very similar, but it's just a shift of the world in XY coordinates (diagonally).
The real seed requires the use of a third party Perlin noise generation library, this will no doubt be added in the future. I can't just take and remake the current generation for some new library, as this will break the worlds that you have already generated. For this reason, I will have to add a new generation "engine" to the world settings in the future, which will have a real seed, and not just a shift in coordinates.