Heh. I ran this as a two-player game (which was really a one-player game because player #2 was player #1's girlfriend and didn't do much except watch) back around 1989 using low (1st?) level characters. I nerfed the combat-oriented encounters (the 4-armed gargoyle, the juggernaut, the mummies), but since there's so little combat and the vast majority of the module consists of level-independent "make the right choice or die" traps and puzzles that are more a test of the players than their characters, I didn't really have to change much. Both characters survived and made it to the end. I don't remember what was done about the demilich -- I'm not sure they even tried to fight it, they might've just grabbed the treasure and left without disturbing the skull (which is apparently what Robilar also did in the original test-run). In retrospect I suppose it's possible that the player had read the module behind my back and was snowing me (and I imagine all you sour-grapes folks will insist this must be what happened) but that wasn't the impression I got at the time. He was just a very good player -- cautious, clever, didn't take any unnecessary or stupid risks or chances.