Bet you didn't expect to see this game up for translation, did you? I mean, okay, perhaps you saw it on the lists but I doubt anyone took it seriously.
Think about it for a moment, though. The Sims has a lot of fans and is a game style that works both better and worse in a roleplay format. True, level grinding their cooking skill isn't going to be as worth while unless you want to introduce some sort of Wii component involving personally doing 10 jump ropes to simulate their leveling up (could be a neat exercise regime?). But there's a lot more to the Sims than that, especially with the Sims 3.
As a Storyteller, you'd need to be very good at roleplaying quirky and interesting NPCs to really pull this one off as you don't have plot to fall back on. Its all about the people and, to a lesser extend, the locations so ensure that the individuals have enough motive and personality to keep the game afloat.
Doing some research into the locations that will matter to the characters - or spending a lot of time creating some interesting ones - will also be very important. One of the major things the characters will be doing is going to places and visiting them so its good to know how to make the environments eye catching and curiosity arousing.
Sims 2 characters have to deal with needs, wants and fears, and aspirations while Sims 3 simply grants positive or negative moodlets according to the characters' personality (made up of five traits) and certain global effects (who likes being humiliated).
I'm not sure how you'd add this into a roleplaying game. Perhaps by handing out moodlet cards after certain activities that have bonuses or penalties on them depending on recent circumstances? It could work. I mean, this is a slice of life game after all. Its not like you're going to be rolling dice often so making it part card game would work just fine.
Moving away from the Sims 3 game to talk more about slice of life games, bear in mind that these are VERY character driven. The players will have to do most of the work. After all, its more about how people feel and what they're up to rather than major plots and firefights. It can help to look at Drama, Comedy or Romantic Comedy television series and see how the plots unfold in those. Generally its about colliding goals and personal issues causing stumbling blocks in the characters' lives. Oftentimes those characters are larger-than-life because they have to carry the entire series on their own shoulders. There's no explosions to draw attention away from them.
I just love looking inside other people's homes.
Unfortunately, there's no real way to do the architecture simulation of building and decorating houses ... which I adore. Oh well. I guess there's always the actual videogame to play for that sort of things. Its not like I can't use it as my map making tool to design my properties for the games.
A campaign based around the Sims 3, or including elements of it, should appeal to Communicators first and foremost. I mean, its a game all about talking to people and seeing what it would be like to, say, be a rock star or a really rich person. It'd be a slice of life game which might not appeal to all Communicators but it'd certainly appeal to some -- especially if the era or location were set to somewhere exotic.
Explorers may well enjoy the chance to voyeuristically explore other places and meet strange people. Tacticians may enjoy the chance to juggle needs, particularly if there are clear mundane plot goals such as going up the career ladder or managing their own characters' needs.
Investigators will probably find it quite dull as this game lends itself more to the Mystery of the Lost Handbag rather than the Mystery of the Decadalion Conspiracy. Action Heroes will, in short, hate it. This is a slice of life game and, not only that, a slice of a pretty mundane life.
If you'd like to take a look at the trailer to learn more about this game, you can check it out here. If you'd like to read the sort of tropes that Amnesia used, you can find them here.
For the next Game Translation, you have a choice of these: Left for Dead, Half Life 2, Skyrim, The Last Express, Gears of War, Mass Effect, Dracula: Origins, Realms of the Haunting, Dragon Age 2, and pretty much any survival horror or horror game. If no one picks anything by next week, it'll be The Last Express.
If you want to see the list of games I've done thus far, you can find the Game Translation series starter over here.