I'm playing the Midnight Sun Challenge posted by Gurra09 on MTS. In this challenge you play a five generation legacy with one gigantic twist: the world you use has nothing but an extremely tiny island barely big enough to hold a 10x10 lot. Literally. As in if your Sim wants to leave home, the only place to wander to is the very fringes of the island. And the real interesting part to me is that they tampered with the world so that it never really gets dark on the island - and sunrise is at midnight.
Now, I've played this challenge once before, and honestly I'm so used to highly restrictive challenges I wouldn't call it that 'difficult' per say, but it is a very interesting switch from normal gameplay and frankly the little tiny island inspired me. I've never really written any Sims stories before, but I find this concept interesting enough to give it a try. And since I have written other things before, I hope that it's halfway interesting for a first one.