Around a wide and empty central shaft, a staircase spirals endlessly down in the darkness. With exact regularity are found openings to spacious empty halls, stretching into the rock.
People live here, in a city carved from the stone to either side of the halls. Their fungal ale and magical rune paint hold back the darkness for a bit... And it's not so bad an existence, now that even legends of the light have passed beyond memory.
Not so bad except that death itself holds power over the levels above where humanity ekes out its meager lot. The bones of the ancestors animate into twisted monstrosities and attack, and previous cities have sometimes fled downwards en masse, abandoning their works.
This is the Well. You are a group of orphans who have had a turn or two as "gravediggers", the odd sorts who attempt to rescue artifacts from higher levels. Now, though, when a madman has carried your den mother up and away, you choose to risk more than ever before.
This is going to be tangentially Amber-related, but the majority of this game is "The Well" by Peter Schaefer. It's a game about exploring, finding things, and killing monsters; it uses a few d6's in a simple and easy-to-grasp way. The kickstarter shows some of the art: https://www.kickstarter.com/projects/shoelesspetegames/the-well-rolepla…
Be ready for a dark, creepy atmosphere and some bitter fights.