Boulder Dash is a popular strategy/maze game initially created by Peter Liepa and Chris Gray for Atari 8-bit and released in 1984.
The game, published by First Star Software, was ported to several platforms, including Commodore 64, Amstrad CPC, Apple II, Atari 2600, BBC Micro, ColecoVision, Intellivision, MSX, NES, ZX Spectrum, and many others. Boulder Dash was so successful that the creators produced an arcade version. A coin-op was released in 1985. It's one of the few cases where a home computer game is ported to an arcade. Usually, it's the contrary.
You are Rockford, and you must dig through the caves, searching for diamonds and avoiding monsters. There are 16 levels to be completed, with five different difficulty settings.
Boulder Dash received very positive reviews, and it's considered one of the best games ever released on the Commodore 64.