Just use WASD or the arrow keys to control your drill, and access the buildings on the surface with the space bar. M opens your map. As you collect ore, you’ll be able to sell it for money, and then you can use that money to upgrade the various aspects of your drill, much like an RPG. That’s the only way you’ll be able to drill deeper to where all the higher quality ores are.
Mega Miner has you drilling your way from rags to riches. When the game begins, you’re but a lowly miner with only a drill and a dream. From there, you’re sole purpose in life is collecting minerals and selling them for profit, and then using that profit to turn your meager drill into a Mega Miner. But there is some strategy and management involved to prevent you from becoming an overnight success. Your flimsy little drill can hardly delve too deeply into before you outfit it with a few upgrades that will not only help you drill farther and faster, but also stay cooler so you can stay in the depths without having to come back up before you melt. You can also outfit your fuel because if there’s anything worse than letting your drill melt, it’s running out of gas and having to be rescued.