Motherload

Motherload is an underground excavator (a little like Crypt Keeper), but with the emphasis on digging out valuable chunks of metal from the Martian surface rather than solving devious puzzles. The man behind Samorost flagged it as one of his favourites and that’s as glowing an endorsement as you’re likely to hear!

So, you spend your time drilling after those patches of metal, then dragging them back to the shops on the surface - before you either run out of fuel or weaken your hull too much (by falling too far). You can spend the money you make on various powerups, but it's still quite a bit like hard work - not that there's anything wrong with that, but we'd expected slightly more entertainment from the makers of Defend Your Castle and Fishy.

Arrow keys (or A, D, S, W) to drill left, right, down or fly upwards, I for Inventory, R - Repair hull, F - Fuel reserve, X - Dynamite, C - Plastic explosives, Q - Quantum teleporter, M - Matter transmitter (if purchased).

It's worth digging out long vertical shafts for when you need to get back to the surface quickly to refuel (just like running a real mine!)