Diggy is a custom RedMew scenario. You start out with nothing but a market, your pick-axe, and some walls deep, deep in the mine. The goal is to launch a rocket but be careful, there’s not a lot of space and the mine is unstable!
The idea of Diggy is similar to vanilla, except that it greatly changes how to build your factory. As you’re in a cave, each rock you dig, each support entity you remove, and every tile you mine, can cause a collapse. You can use walls, stone paths, and (refined) concrete floors to increase the strength of your mine and reduce the chance of a collapse.
Whenever you place or remove a wall, for example, the stress level of the area around it (9×9 tiles) will raise or lower. When a certain threshold is reached, the cave will collapse. You can stop this by quickly placing walls or running away as fast as you can. Letting the cave collapse will destroy structures below it! The recommended pattern on dirt is to place a wall every 4th tile. Using stone paths and concrete will increase this to 5 tiles while refined concrete will make it 6.