>>374
any top-down shooter is a space invaders clone, technically...
you have to remember that Touhou's been around for a couple of decades by now, and was made by only one person for the most part; the games are kind of like the progenitor to what we'd describe as the indie scene now. combine its age with fun (and/or challenging) gameplay, high replayability, a cool world filled with likeable characters, yet not super heavy on story so there's lots left to the imagination, and good music, and it's not very difficulty to see why it got popular initially. its enduring doujin scene and dedicated fanbase continues to keep the series and its fanbase not only relevant into the current day, but also still growing.
