My first idea was to have it on like the moon with everything in the game now under one huge dome which is only visible when you go to the map screen.

Anyway, here are some more ideas I've had:

fire - home made generator that uses fire to run
statue - "supporting" column for the dome (needs to be fixed to make sure dome doesn't collapse?)
fishing - mineral gathering (sharks=aliens?) since only the head is shown in the water I was planning on putting them in a "space" suit

also, as for the background story, here's what's been bouncing around my brain:

Just as with vv3, a family ... ok, let's just steal the Lost in Space plot but have the family crash land on an asteroid where they find an ancient human space colony now in ruins but still supports basic life functions (air, food, etc.) their crashed ship (wood pile near honey) gives them some supplies for building / fixing structures and the rest of the plot sticks with vv3.