We've added a couple mechanics that you don't find in basic mafia, one of which is similar to roles I've seen used before ("The Owl"), but the other ("The Rat") is totally unique as far as we're aware. In our game, Rats are typically "civilian" equivalents, but when choosing to play with their optional ability, they have a chance to identify one another during the night, giving them their own unique objective, like other players have.
Other than that, the biggest difference is not having to use a regular deck of cards. Everyone's ability is written on their card and the narrator is given reference cards to help things run more smoothly for players that are less experienced.
There are other Mafia-inspired games, but they all give you their own laid out set of rules. We designed our game to give just as much freedom to customize as a poker deck. We give you blank cards, so you can write in whatever roles you like, and even our "Serpent" and "Rat" cards are numbers, so they can be called on individually if necessary. We really just tried to make sure that any obscure way someone likes to play the game can be accommodated.
Our rules or your rules. You pick.
And the artwork is really cool. I'm not the artist on the team, so I can say that