Zoom in, zoom out.
This game is a universe generator. Each map is 10×10 tiles, and clicking on a tile expands it into a full map of its own representing a region of space ten times smaller. The scale of the game ranges from a 10 billion light year universe map to a 1 attometer quark map.
The game is made in Godot Mono 3.4.4, which can be downloaded at https://godotengine.org/download/windows.
For C#, the .NET SDK is needed, which can be downloaded at https://dotnet.microsoft.com/en-us/download.
Once Godot Mono and the .NET SDK are set up, the project can be imported into Godot by opening Godot, choosing "Import", and then importing the project.godot. Depending on how Mono was set up, Godot might not like building it straight away; if it gives a strange error like "build tools not found", check to make sure the .NET SDK in installed and otherwise in the Godot editor try Editor > Editor Settings > Mono > Builds and choosing a different build tool.
Things that would be nice to have in the game are in the Github issues https://github.com/TetraspaceW/VanDNationGame/issues.