Extend the brass arm, grab a gem, retract before the blade
Deep in a narrow mine shaft, gems sit embedded in the rock far above your base. Your tool for reaching them is a telescoping brass collector arm with a claw at its tip. Hold the screen and the arm extends upward, section by section, climbing towards the stone. Let go and it snaps back down into the base — and that retraction is the whole point, because a gem only counts once the arm has carried it all the way home.
The complication hangs in the middle of the shaft: a spinning blade that sweeps across the arm's lane. The arm has to be fully clear of that lane before the blade crosses the centre. So every grab becomes a small calculation. How long will the hold take to reach the gem? How long to haul the claw back down? Is there room in the gap between sweeps, or should you wait one more pass and go on the next opening? Hold a fraction too long out of greed and the blade arrives while your brass is still stretched across its path.
The game runs for fourteen levels, and each one adjusts the same equation rather than replacing it. The blades turn faster, shrinking the windows you have been reading comfortably. The gems retreat deeper into the shaft, so each hold has to run longer — which means committing earlier and trusting your own timing further. From level six a second blade joins the shaft, and the two of them produce gaps that open and close in patterns you have to learn rather than guess. From level ten the blades begin reversing mid-sweep, which punishes the habit of assuming a blade that has just passed is safely gone.
The controls stay as simple as they started: one finger, one hold, one release. Everything difficult lives in the decision of when. This is a game of patience and nerve, of counting a rhythm in your head and then having the discipline to let go at the right instant — not a moment early, and never a moment late.