Factorio seems especially well suited to TDD. The core gameplay loop involves automating away manual tasks. So I have to imagine that the test cases leverage

Factorio seems especially well suited to TDD. The core gameplay loop involves automating away manual tasks. So I have to imagine that the test cases leverage blueprints a lot, i.e., create a blueprint for a feature, pipe resources into it via conveyor belt, test output rates on conveyor belts.