I can say that I struggled with finding sources at the beginning as I couldn’t find decent sources on flow for video games area. And even thought about changing the topic. But from second attempt I managed to find some relevant academic sources, most of which, I believe, would be useful in the long run. At least I have found major source on flow and two methodologies that will help me to build methodology.
As for research question, it hasn’t changed greatly and still conscerns flow in Pathologic 2 and the Void. I took it specific enough to additionally narrow it down. And since I have some sources now, I’m not going to change it.