So something I found interesting in INITIATE SEQUENCE, the Tron Legacy "choose your own adventure" book:
If you choose to ditch Quorra at the games (“GET IN USER WE’RE GOING SHOPPING”) and make a run for it, you jump down into this sub-level of the Grid, which is all decrepit and abandoned. All the buildings are crumbling and its rusty (I had never even considered rust on the Grid) and freezing. So you (Sam) go into this old factory of some sort, where you begin to get taunted by voices. You fall through a trap door and break your neck (“you know, for kids!”) and then as you’re dying you see that the voices belong to “ghost programs”–programs that were deleted (I’m thinking deleted improperly from the outside) and dwell in a ghost-like, glitching form in lower Grid levels.
I thought this was so interesting and really eerie, and I had to share it with you guys!