Haha, I actually did use ren'py for this game! I don't mind giving more of the technical side of how I did things, just let me know what specifically you're curious about.
I'm also thinking after the update, I'm going to make a post mortum type post where I go in depth on how I did everything and my process (or at least best I can). On my tumblr, I also had a dev log going that I talked about some of my progress as well, if you're interested.