nice map

The nats are really big and spacious, I recommend shrinking them a bit.

The sprites are pretty and all but in some areas, like around the ramps, I might remove some of them. They seem a bit distracting. Also, take into account that sprites are just that, basically a floating image in the map with no attributes. They don't take up walkable space, so putting them in the tank holes behind the nat doesn't do anything, just makes it harder to see units under there.

The nat is tankable from the high ground right next to it.

Middle can be split completely if you draw a line horizontally. Don't think it's likely since it's so big but it might make end game scenarios a bit boring, especially since the middle is so bland (just an open wasteland).
modified by JungleTerrain

Also realized that the download and the picture are not the same version.

Mineral only seems too vulnerable for anyone to take. Your ramps need work, as well.
modified by JungleTerrain