Keeping up with expenses is extremely easy, so there is no challenge beyond the first day, when you have to figure out the mechanics. There is no story after 7 days, so I'm assuming there is none, which is a shame, since the description suggested some mystery (I even tried hunting for the forbidden fish on both maps, just to see if I could provoke DAC or something).
The base is shaping up really well, and the visuals are nice, but it needs more content.