I started my current main save as Realistic (Fictional context) with only androids, but over time introduced aliens, ghosts, servos and paranormal activities to my setting. The world includes lots of real world elements that I wouldn't want in my own life (or anybody's, for that matter), like job shortage and prejudice. Technology is just advanced enough to allow for the backyard rocketship and freeze ray to exist, but not to make them common household objects anybody could own.
Sims don't age, everything happens in a perpetual state of "the year was 204x". Sims also cannot die from random occurences like emotions or falling during mountain expeditions, but I feel oblidged to work the near-deaths in as crippling/harrowing experiences. My sims have to face consequences, although more often these result from my own scenarios ("Employee evaluation time, dear simmies!") than from ingame ones ("Stupid chance card, you never happened.").