One day I'll write a book on the post-2000 indie games resurgence, but in the meantime there's now a cool free ebook by Ben Latimore (creator of the excellent Flashpoint preservation project) about the heyday of Flash games. https://archive.org/details/flashpoint-a-tribute-to-web-games/

@wildweasel Glad to hear/read it! I'm writing two new books at the moment (one's a genre history, the other on the creation of Age of Empires, both to be manuscript-complete this year), but the indie games book is on a shortlist of several options for the next book after those.