Short tips
Make them connect on a 45 degree angle, looks nicer.

The left side here seems a bit bare, Maybe have a walkway turn an open corner there, not connected to the other floors in the room by stairs.

Remove the hole. It has no real use and would annoy the humans falling through it in battle.

The large outdoor area has too few exits/entrances for its size
Maybe have the lower area in the corner there have access to 1 or 2 corridors.

Or a corridor exiting in the corner there.

This is all to make it a more central point of the map.
Long term thought

As you can see the map is pretty straightforward and circular. Try to weave more so you have a lot of paths and turns you can choose from. This makes it more suitable for 'real games'. With real games i mean where base moves are encouraged. You can actually hide eggs. And escapes aren't necessarily back to base.
Another point is the fact that the map doesn't have many base suited locations. I think it's sad since a map like this has excellent potential for it.
Also remember to have a couple of somewhat more cramped rooms connected for alien bases. Most rooms now are too big and don't have the right angles for a good alien base.