[DustyPorViva]

My opinion on linear dungeons is that you should have a direction for the player, but give them the illusion they are making choices. If you make dungeons too open-ended then it simply confuses the player and that can lead to frustration. But if you make it too obviously linear then that makes the player feel bored because they feel controlled. However, laying out a clear path and direction, yet masking it with a few open rooms and choices can give the player the impression they are choosing their path while you're still defining the direction they go. Also, backtracking is also a very important part here. If the player is always going forward then it's quite clear that they're being guided. But if they have to backtrack between areas they've been then they lose focus on the fact that there is a clear path and focus more on trying to remember the layout.

All in all, you can see this kind of thing all over Zelda dungeons. You enter a dungeon, and you are given a few paths. You can take either path, but eventually you will end up going back to the main room because one end results in a treasure of sorts. Either a map, compass or a key. They you have to backtrack and go the other way. This leads the player deeper into the dungeon. Eventually the player may even go around in a circle, cleverly linking the layout in some way. This is always a good feeling, to feel like the dungeon isn't just one direction. Throw in a few secret rooms to pull the player away from the main path(bombable walls, or paths that simply lead to minor prizes... or even paths that aren't accessible until the player comes back with a new weapon, this is ALWAYS great). All in all, it ends up being an experience that clearly has one way to tackle it(you will always get the exact number of keys that need to be used exactly as intended) but lets the player feel like they're in control.