Been playing this for a few days and, after building myself a neat little shelter and lighthouse I set off to explore the nearby caves with a healthy supply of pickaxes, torches and shovels.
45 minutes later, undoubtedly now at least a day's trek from home and buried somewhere miles beneath the earth (one cave leads to another cave leads to another cave and...) I ran out of digging implements and thought it best to head back to the surface and trek home with all of the ore I'd managed to collect.
I retraced my steps, back through the twisty caverns and trail marked with torches and suddenly came upon an open space, which I'd clearly passed through on my way down as there were numerous torches dotted around, but... There was no obvious way out. I then ended up spending the next 40 minutes wandering around in circles without a clue as to where this supposed exit was.
It got to the point where I'd exhaused all hope and, with cabin fever setting in, I started throwing blocks down into a tower, right to the ceiling, where I planned to say my last few words and jump to my demise. If I was going out with no loot, I was going out with a bang.
As the roof got closer, I reasoned that a drop from this new tower wasn't going to be enough to kill me in any spectacular way, so I dug upwards into the roof of the cavern with my bare hands, scrabbling at the dirt, the last act of a desperate man. Once. Twice... Then, there were white dots. Confused, I dug another block. More dots.... "The thing's hollowit goes on foreverandoh my Godit's full of stars!". I'd found my way back to the outside! A journey time of the best part of 2 hours in total and I was going to make it home with my loot after all!
Then a spider hissed, dropped through the hole I'd created and slaughtered me before I had chance to react. I never saw the loot again.
Best. Game. Ever