My greatest complaint in the Penumbra series was trail and error. While the game is terrifying and very immersive, there were points were I had to restart due to not saving often enough, as saving itself breaks immersion.
After that, now that I knew the layout of the zone and also know that unless I hear the dog there is zero danger, I could wounder around freely, with little or no emotional impact form the spooky environment.
I think the holy grail of gaming is a interactive story that has no back tracking, each decision leading to the next and so on.. but the shear complexity of trying to predict and build gameplay for all the possible outcomes of any given situation is not, I believe, possible.
A terrific example of trail and error gameplay that works.. to a point. Is that ps3 title, Hard Rain. During the first playthough it is like watching a engaging film.. though after some restarts and save points and then trying to get the "best" results, the game turns into something more like guitar hero.. just button pressing and memorization.
There are other ways besides death and multi-paths to give a continual feeling of immersion though and discourage restarts. One that I believe is very good and works perfectly for heavily story driven games is a evolution of the character you play. A simple example is the character evolving to be a "evil" or "good". As with out changing the core gameplay of the entire title you can modify the reactions and abilities (options) the gamer has during the game to get past zone blocks. This can give the player a real feeling that his actions have physically changed the gameworld. Unlike "good solution" and "bad solution" witch as stated in this thread can be as frustrating as player death and encourages restarts. This method of changing the way the character can interact with the world bases on previous game choices can create a continual momentum of story, witch the player wants to continue though even though they might believe there was a "better" way to play said given part of the game.
PS- I would just like to also comment that I really enjoy the well though out gameplay discussions the frictional guys foster on this forum and on their blogs. To a long time.. maybe "to heavy" gamer, I find them extremely interesting.