I’m gonna be honest, Mastodon is kinda trash, on its own. It’s clunky, ugly, and feels like a platform from 2010 (but not in a good way). I think getting people onboard with a Misskey/Sharkey instance is going to be much better. The feature set is a lot closer to Twitter, and it does literally everything Mastodon does, but better.
They’re usually put in the game’s credits. The promotional material is part of the game even if it isn’t on the disc, it isn’t some separate project that exists in a vacuum.
The author says “think about it”, but clearly he didn’t.