Overheating - your cards no longer run by themselves forever. Every card overheats from time to time: it flashes orange, shows OVERHEAT and mines at half speed.

Broken cards - an overheated card that nobody fixes within 20 seconds breaks: it turns dark red, shows BROKEN, stops mining and stops dropping coins.

GPU tablet - a tablet on a stand by your pit, wired to the rack with a cable. Walk up to it and press E: it lists every card you own with its level, shelf, place on the shelf and how much it mines, broken cards first.

Cool and repair - an overheated card on the tablet has a COOL button, a broken one has REPAIR. Press it and the card flashes green and gets back to work.

Better cards are fussier - a potato runs for about 100 seconds before it overheats, the best cards for about 55. Keep an eye on your top shelf, that is where the money is.

Warnings - the screen tells you how many cards are overheating or broken, a short beep plays when a card overheats, and a fan dying sound when one breaks.

Arrows to the tablet - when a card breaks, a row of glowing arrows on the ground leads you from wherever you are to the tablet.

Cooling - a new upgrade in the Upgrades menu: cards run up to twice as long before they overheat.