Errant Kingdom is a visual novel with text-based elements, which, I assume, means you have to have some interest in reading to appreciate it. I find it ironic that some people don't even bother to read the synopsis/description in this page, to see if the information they are looking for is contained therein, yet play a game of this nature... It says on the very first two lines of this page:
"Errant Kingdom is an episodic release and will update in volumes/chapters on a bi-monthly (once every two months) basis."
If Chapter 3 released yesterday then we can assume the next installment will be up sometime in October.