cut gems · hold the light · keep the dark out
Deep beneath the planet's surface is a world called the Deepunder. The gnomes of Glitterdelve live down there — the last warren of them, as far as anyone knows. There is only one way to survive this far down, and that is by light.
Especially since the dark isn't empty. Something old waits in it. It is powerful. It is hungry.
So the gnomes cut gems. Gems power the light, and light pushes back the dark. From the great heart-shaft at the center push their domain further into the Deepunder, using their wit and ingenuity to conquer an inch at a time. Maybe, they hope, they can reach the ancient evil before it reaches them..
Cut a match. With the Cut tool, tap a gem and then a gem next to it to swap the two, or drag one onto its neighbor. The swap only holds if it lines up three or more of the same color. Line them up and the gems are cut. That is your work, and your score.
The heart-shaft. The middle column is the one light that never goes out. It feeds itself a gem every beat, and any gem that reaches the bottom of it is collected. That is where the light comes home.
Race the fall. Every other lit column only reaches so far down. A gem that falls below the light dims for a moment, then it is gone — lost to the dark, and the dark does not give it back. Gravity is always trying to drain your gems past the edge. Matching is how you beat it there.
Push the light outward. Cut a match in a lit column and the light claims the next warren over and keeps it. Reclaim them one at a time until the whole delve is lit again. The count top-right tracks how many warrens are lit, and how many gems the dark has taken.