This is more of a general RPG topic than SE, but more specific than Gen Gaming, so... whatever.
What makes a video games world 'vast' to you. In the thread about what you liked about each FF I noticed a few people praising FF12 for having a vast world. One of my main complaints about FF12 is the world feels very diminutive. So obviously we aren't all judging by the same criteria here
So, what makes the world feel 'vast' to you? Or conversely, what are the flags that make it feel small?