Yeah, that's the theme of the map.Yes, but it is Space invaders... Look at the Videogame : http://www.freeinvaders.org/
It should be something like a black dot, which fits with the theme of the background of space invaders (use coal blocks, obsidian, black stained clay and black wool, make it have a variation. ;))
This is an island. I have to build the middle!Looks better than before, however, the bunker looks plain and the islands are very close to the middle.
A map can never, ever be too detailed imo.That looks a little bit too detailed IMO, with the space invaders theme, it's all about simplicity. But yeah, looks pretty cool.