Den Mine 15

An Emerald Mine\Boulderdash game created by Denis Forde with the Emerald Mine Editor and published commercially by the Emerald Mine Club in 1996. The player is deep down in a cave and has to collect emeralds and diamonds while evading monsters - and the laws of gravity, which have the annoying habit of squishing him with huge rocks if he happens to stand beneath one as it falls down.

The game also has a two-player mode where two people can rid caves of their valuables at the same time.