Dwarf Fortress

When it comes to 4X, the first two x are the best x, aren't they? The peeling away of mystery, the bringing of light to the world - rolling back the fog of war to expose terrain, neighbours and sweet, sweet resources. Adventure, discovery, the era of Magellan rather than Cortes: this is what drives me to the genre again and again. It's why I've started thousands more games of Civilisation than I've ever finished, why so many games of Endless Legend are left to digitally moulder: I am a scout, not an administrator, a Lewis and Clark, rather than Pricewaterhouse Cooper. The fine print exhausts me.

In December 2015, Dwarf Fortress players started discovering dead cats. An update had just gone live and clearly there was a problem buried somewhere within its code, but even the game's cocreator, Tarn Adams, didn't know what that was.