Unity CEO John Riccitiello came to TechCrunch Disrupt SF to give everyone an update on the world’s most popular game engine. You might not be aware that most of the games you’re playing, especially mobile games, are built using Unity. For those not familiar with game engines, Riccitiello started by describing game engines very clearly. Back in the days, “[game developers] would write out a game program that had lots of art assets, lots of animation, lots of sounds.