EricNoah said:It helps when, with experience, you get good at disguising linearity a bit. Bending, twisting, the third dimension, etc. can help, as can the occasional branch or self-contained loop.
I think the thing to keep in mind about linear versus branching or looping design is this: with linear design, the flow of play is predictable (which has upsides and downsides.) The less linear you are, the more randomized the number and nature of the encounters is, and you get things like two different groups reporting entirely different experiences. Non-linearity essentially randomizes the number of encounters in the game.
This can be important if you are trying to manage your time. Nobody wants to be stuck in the middle of a dungeon on the last game before a vacation. On the other hand, I have no problems pulling out a nice branching/looping dungeon like Rappan Athuk or Undermountain if I am just interested in running a few encounters and kicking back with some friends, and am not really concerned about reaching a goal at the end.
THAT SAID, I use Undermountain in a fairly linear goal-oriented fashion fairly frequently, simply by providing maps and guides. So sometimes, the wall and corridons don't tell the whole story.