Thank you so much for leaving a comment and being a long-time player! And I'm glad to hear you enjoyed the demo ^^
If it helps, I made a (really basic) resource post on Tumblr about how I made 14DWY! I wouldn't be able to do a lot of the things in Ren'Py without some of the stuff mentioned there :3 I'd also suggest looking at the credits menu for the assets I didn't make myself!