This is a Sim’s game, pure and simple. You don’t have any story laid out for you; you create your own by crafting your own colourful cast of characters (and now their pets) and interfering in their lives as you feel the need to.
It’s a sandbox on every level, providing you with the tools to create and build, then just lets you experiment and see what the results are. You can try your best to keep your household happy and cater for their every whim, or you can be a complete bastard, torturing them at every opportunity; it really is your choice. You can’t win, you can’t lose; you just play.