Goat Sim is described as being a "physics sandbox", and essentially provides a playground for people to cause chaos. Despite the name, it's about as far away from being a simulator as is humanly possible - instead, it's a place to mess around, and make your friends and family laugh as your goat gets into all sorts of impossible situations.
Goat Sim has been designed to be as ridiculous as possible, and in that regard, there's been a bit of artistic license taken with what a goat can actually do. While real goats mostly spend all day sitting around chewing grass, this one can ride bikes, use a jet pack, become a hockey stick, leap on a trampoline, get flung into the air by a fan, and no matter how far it gets thrown, or how many explosions it causes, it still gets back up and carries on as though nothing had happened. Oh, and it has an incredibly sticky tongue that lets you take objects, or people with you through the levels.
In terms of what you actually do in Goat Sim, though, the choice is pretty much yours. Although some guidance is provided by way of a small number of challenges (mostly for earning more than a certain number of points, or doing tricks like an extreme sports game), and there are some interesting trophies to unlock (many of which have cryptic clues), which in turn unlock new abilities in the game, Goat Sim is mostly pretty free form, and you're expected to make your own fun. While that can be easier said than done if you'll be playing on your own, Goat Sim comes with full support for four player split-screen on PS4 and Xbox One (two player on PS3 and Xbox 360), letting the whole family join in the fun - and you'll be in fits of laughter from the moment you pick up the pad. While those who prefer their games with more structure may find the lack of any real objectives disappointing, as a party game you pull out every now and then, Goat Sim is worth a try.
With nothing in the way of swearing or sexual content, and no real violence, there's nothing for parents to be too concerned about in Goat Sim. While you can cause explosions which see your goat being flung across the world, and there can be some pretty painful looking collisions (you can be run over by a car, or flung into a building after being clipped by a roller coaster), there's nothing in the way of blood or gore, and your goat simply gets straight back up again as though nothing's happened, showing no ill effects.