Emerald Mine is a Boulder Dash clone created by Kingsoft in 1987 for the Amiga and later ported to Commodore 64.
The mechanics are well known: you have to collect the emeralds digging the mine, trying to avoid the rocks that will fall when you dig below them: simple, 8-bit style, graphics, but great gameplay. The best part is the possibility to play in 2, with 20 exclusive levels.
Emerald Mine was one of the most appreciated games during the early years of the Amiga, and it still has an active group of fans that continue creating custom levels. Perfect for a quick match with a friend.