There is a lot of domain specific knowledge for sure. There is a huge difference between, "I made a flappy bird clone/shitty side scroller in Unity" vs someone who actually knows how to make a triple-A level game. The former requires, can you spend 4 hours watching youtube videos on a saturday night and literally just mimicking the video. And there are people who become the latter developer starting as the former. But there is a lot that has to happen in between.