Vision

I was thoroughly enjoying this, until NoScript popped up, telling me a script was trying to interfere with mouse and keyboard interactions.

Remember to use vaunt, destroy the small carts before the main one and destroy the buildings.

Gunner or Laser is probably your best bet as far as ships go.

A good way of knowing if you can, for example, place a torch:

The cursor is context sensitive. If you get close to a wall and move your cursor close to it(While you have a torch in hand) the Torch icon will show up by the cursor.

And like Laughing_Man said, left click to place stuff. Q to drop it.

I made us a house with some stuff. :)  (Such as a hellforge)

I'm on right now, making a tunnel to hell.
 
EDIT: Tunnel to hell is complete with safe landing. I got you guys a hellforge aswell.

I can play a couple of Coop games with you, so you can get the hang of it. :)

Q3DM6