I ran the necropolis twice at kantcon 2017 in Overland Park , ks.
first session had three players, second had a full compliment of six.
Both sessions ran for about 2.5 hours (I tend to slow burn with atmosphere and allow players to play in the sandbox a little bit to get familiar with mechanics).
in both instances, the game ended in total party kill- thanks to the soldiers use of dynamite.
The first session never got anywhere near the jars, and actually ran scared at the sounds of he creature breaking free.
The (first)soldier made a critical fail on planting the dynamite at the barred entry door. I ruled the whole tomb collapsed.
The second party did really well with finding the clues, and even formulated a plan of attacking the monster, and indeed- it sure was squishy.
again, the soldier with dynamite, fumbled the throw roll- dropping the lit stick amidst the entire party. Regrettably he was already out of luck, and even when I gave him a sympathy push- he just didn’t deliver..
everyone had a BLAST , as I had already prepared them to the idea that in coc, it’s not a matter of if you die- but WHEN.