One galaxy
Thousands of sectors in that galaxy
10 to 30 star systems per sector
Six planet types, including artificial ring worlds that make Halo shudder in awe
Hundreds of Thousands of different plants and animals
The foundations to forge your own empire, your own destiny, literally from scratch.
The ability to design and construct interstellar starships and trade or conquer other empires in other systems.
Seamless space>planet transitions.

all for 200 megs of space.
What more could you want in a space simulator?