What causes the scene outside the Death Star to change?
As far as I can tell, it's related to the total number of floors.
- 1st change: Around 25th floor
- 2nd change: 55th floor (two flying droids and a big one)
- 3rd change: ???
And so far the bottom of the death star remains unchanged.
I got the second change when I reached 35 workers.
Here is a picture of this:
Here it is folks. 55 Levels and these guys showed up on my TDS!