In short

All game logic is written using decent 'mh responsibility driven design', also called Inversion of Control. Components implemented are all unit tested (as automated as possible).

Next there is the actual 'biiiig' test that works with the Simulator and ModelObject framework to combine all these features into the actual RTS game.

Note: is is allowed to make more than 1 big test, but the reason of creating these extra tests should not be for testing features, but for cross cutting concerns like: performance, network sync, … This bigtest should not be considered a unit test (it isnt a unit test), but more like a sandbox environment. Also: found a way to define when something should be in the simulators and when it should be written using IoC. If you wrote a unit test, it should be IoC (and pls do).