Mission 3 : Collect your first materials.

Do not rely on the appearance : there's nothing on the top of the blue central area... but there's a lot under.

In order to collect the needed materials, you'll have to dig on the ground. It's a tedious job. And you'll have to do it for a very little time in this first part of the game. But the good news is that Blackvoxel isn't a game about hand working and you'll have some machines to do it for you very soon.

For grabbing a block, press and hold your left mouse button (or the "C" key) while pointing to it with the croshair.

Now, dig a descending staircase into the ground. You need to to dig dig enough to reach the green layer at -64 blocks deep. Do not forget to collect all materials you'll find on your way. At least, those that aren't too hard for your tool.

Once reached the green layer, collect at least 8 BlackRock Green.

Now, you can go back to the surface and go to the next mission.