no, that the space, as in the final frontier, is extremely obviously shaped like a cube. Every game does it like that, but most games don't have half of their stars on their borders and try to mask the lines and corners with nebulas, bright stars, dust clouds, asteroids, etc.
games like EVE, as the best example of space
Of course it is intentionally cubic, but you don't want the people to see that now would you ? It really kills the atmosphere.
I was referring to the geometry. However I don't see what you're talking about regarding the skybox...