I'm not so sure that a comprehensive test coverage is beneficial for a product like a game which is not really maintained over a long time period. Imo the bigge

I'm not so sure that a comprehensive test coverage is beneficial for a product like a game which is not really maintained over a long time period. Imo the biggest benefit of unit tests is for catching regressions, but a game you get working once and then you're done. Especially for smaller casual games I don't think that it's necessarily worth the effort to write comprehensive tests. Also, as Dijkstra already said, testing is inadequate. It can only show the presence of bugs, never their absence, so even if you have 100% test coverage it really says nothing about the quality of your code or how much you care about it.