I sometimes get down to the last rocks in the whole level before the stairway shows up. I am curious how it triggers, is it locked to a specific rock somewhere in the level, or an n'th rock mined and the chance begins increasing as you keep mining until it appears? I feel like i go through an entire energy bar on 1 level and i'm frustrated.
Early game specifically, have the ore for a copper pik just haven't yet, so i can imagine it gets easier as you go, but i'd still like to know if it's better to mine all the single hit rocks, or if it's pre-placed and you have to hit them all anyway or if you go for the 1 shot rocks first and after so many it appears?
