Anyone else here heard of ChoiceScript? It's basically used to make "choose your own adventure" type games, and it's beginner-friendly too. I've played around with it in the past, but never felt like making a full interactive story with it. It can have some cool uses on VPS sites though. Maybe it can be used for minigames, interactive lore, or just general documentation. I've never tried to integrate it with something like PHP, but I don't doubt it can be done.
For ease of use, there also CSIDE (what I have) which allows you to test your game without having to load it in a browser.
For ease of use, there also CSIDE (what I have) which allows you to test your game without having to load it in a browser.