How important are efficient mining strategies?

I also tend to get obsessed with getting every single piece of ore. One of the things I learned to do is minimize the amount of straight down digging I did. If there was somewhere I wanted to get to without checking thouroughly, I would add little side areas every three squares down. You don't need every other square, as you can dig up. One sideroad every three squares down will be the most efficient. That way, if I ever needed to check for ore, I had my ledges to do so.

When I wasn't going straight for a door or water or something, I would do my best to dig those ledges out sideways as far as possible. If I'd run into a roadblock, I would prefer to get around it from above, to ensure I wouldn't block off any ore I might have missed.

Generally, though, unless you die a lot, you won't need all the ore. There's easily enough to buy all the upgrades, and give you a decent amount for consumables like dynamite and teleporters. And efficient mining strategies aren't that important, as you will eventually get upgrades that let you dig upwards more than a single square.

If you stand on the edge of a block, you can mine more than one block to the side.

In the image above:

• Mine one dirt block to the left and move there.
• Mine one dirt block down and move there.
• Mine one dirt block to the right but do not move there - stand on the edge.
• Mine one ore block FURTHER to the right.
• Jump across to collect the ore.