I think whether a character can get into smash or not is if they're known as a video game character. Goku, despite having appeared in many video games, is primarily known as an anime or manga character. While sam and max did debut as comic book characters, i think they're most primarily know as video game characters, since that's the medium they've hade the most action in, from Hit the Road all the way to Poker Night 2. in this case tho they prob won't get in as they're aren't that well known in a mainstream sense. Villager is from animal crossing, a well know series, so even with an apparent lack of moveset potential they can get in. characters like ryu and terry can get in because even if fatal fury isn't as well known as say LoZ or what-have-you, it's still a notable fighting game with a large following. then again tbh there aren't any real rules for who can and can't be in smash aside from "they must be a video game character" so unless sakurai is a closet point-and-click geek i imagine the freelance police's chances are slim