This isn't a downloadable computer game with 3-D characters and worlds. It's a
Play-by-Post Roleplaying Game. There are plenty of places around the site that explain the rules and workings of 'Souls, and none of them include any notation of a Massively Multiplayer Online Game, which you appear to be looking for. If you would like to know more about 'Souls itself now that you know it's not a downloadable game, feel free to ask.