Most of the time, it isn't terribly difficult to slot games on Steam's best-sellers list into categories. You have your multiplayer survival game of the week, your triple-A hit, your discounted indie, PlayerUnknown's Battlegrounds, and so on. West of Loathing, though, defies categorisation. It marches to the beat of its own drum, spits into its own spittoon, and tells its own poop jokes.