Pleonexia

Your rusty mining rig sits on the edge of the richest seam on the planet. Drill down, fill the ore bin with coal, tin, gold and diamonds, then fly back up before the diesel runs out. Sell the haul, upgrade the rig and go deeper. The core of the world lies 2,890 km down.

Not everyone wants you down there. The voice messages start with a worried neighbour and a water board, then permit inspectors, seismologists, the army and finally the President. The deeper you drill, the more the ground shakes. And under the core, something old has been waiting for a very long time.

How to play

• Move with ← → or A D. Push into rock while on the ground to drill sideways.
• Drill down with ↓ or S. You cannot drill upward.
• Fly with ↑, W or Space. Brake before you land: hard landings damage the frame.
• Surface: park on a building's pad and press E or Enter. The Service Center round the headframe refuels the diesel tank (Fuel Pumps), mends the frame (Repair Bay) and fits new parts (Upgrades). The Assay Office weighs, assays and buys ore and finds. The Supply Store sells jerrycans, weld kits, blast charges and hoist calls.
• Items: 1 jerrycan, 2 weld kit, 3 blast charge, 4 emergency hoist.
• Watch out for firedamp, sour gas, artesian water, hot brine and rockbursts: they look like plain rock. If the frame breaks or the tank runs dry underground, a mine rescue crew winches you up, but your ore is lost.
• Quakes grow stronger the deeper you have drilled. A seismic alarm sounds a few seconds before each one; rock falls through open shafts, so shelter under solid ground.
• Below the core lies Tartarus. Each Titan has a glowing weak point: sit against it to drill into it, and a blast charge packed against it cracks it open (one charge per weak point). Every attack glows before it lands, so get out of the way. Fell all five Titans to win.
• On a touch screen, hold the on-screen arrows to drive, drill and fly, and tap the item icons to use them.

Progress saves automatically.