Jacob's Matrix is interesting because it actually displays a Jacobian matrix describing, somehow, the way that the pieces of the world are put together. Walking from one piece to another can cause you to be rotated or mirror-imaged. You can also create portals (as in Portal) http://www.zincland.com/7drl/jacob/ http://www.roguebasin.com/index.php?title=Jacob%27s_Matrix
Here's another one. This one deserves mention because it turns out that enemies path-finding in a non-Euclidean space will run circles around a human. At least, I think that's how they do it. I have never felt so humiliated by a game AI. http://www.zincland.com/7drl/kobold/ http://www.roguebasin.com/index.php?title=Smart_Kobold
Although, that being said, someone who spends a lot of time in caves may be better.
Jacob's Matrix is interesting because it actually displays a Jacobian matrix describing, somehow, the way that the pieces of the world are put together. Walking from one piece to another can cause you to be rotated or mirror-imaged. You can also create portals (as in Portal) http://www.zincland.com/7drl/jacob/ http://www.roguebasin.com/index.php?title=Jacob%27s_Matrix
Here's another one. This one deserves mention because it turns out that enemies path-finding in a non-Euclidean space will run circles around a human. At least, I think that's how they do it. I have never felt so humiliated by a game AI. http://www.zincland.com/7drl/kobold/ http://www.roguebasin.com/index.php?title=Smart_Kobold