Understood. However even then I would hope that games have unit tests and other module tests that can run just a subset of code and not the entire game. When I'm writing code I want to know it builds and the basics work before I run the entire program.

I work on seasonal programs. I can only do fully realistic tests in the month of April (depending on the weather it shifts a few weeks) , meaning my window to test is closed for the next 11 months. I have learned to find ways to run my code in less realistic situations.