Once it finishes generating, press the arrow keys to move the green sprite. The variable will show you what block you are touching. Don't go off the screen, or the sprite will misalign. :)
This is a test for my generator. Eventually, such a sprite as the one shown here will be used to determine which block the player is mining. Later, I will add a list-based inventory system, and a way to break blocks. I hope to add all this in Urania2Craft before Beta. :D