First things first: It is a compiled EXE. Due to the way it uses INI files you must run it from a fixed location and have the included INI files.
This application is a 2D mining game. To move, use the arrow keys. To mine a square of material/rock, you must hold Q until the block disappears. It is added to an inventory (not yet on screen) and in future versions these worlds can be saved, inventory and all.
You can move through air, and into a block with air on one side of it to mine it. If you get stuck somehow, simply mine that block to free yourself.
To use the developer console, type "dev"+Enter. A new menu option will appear, allowing you to use custom tools (there is only one, called supertool) and allowing you to view your inventory.

For anyone that wants the link, I can happily provide a ZIP file with a compiled EXE (scan for viruses to double check, I don't want to infect anyone), and a few INI files.