Rock Fall

Description
Rock Fall is a 1-player arcade game for the BBC Micro and Electron.
After travelling for many months, the player has finally arrived at Gamma-4, a small asteroid rich in crystals. The player must now guide their mining droid through the soft earth to the crystals. The player moves in the cardinal directions and, if they dig underneath rocks, they will fall, crushing the mining droid. The player has 500 time units to collect all crystals on each level. The droid has the ability to shift all items in an entire row to the left or the right, allowing access to new areas. The player starts with three lives.
The program came with an editor to make custom levels.