Well, I hate ash maps, but I made one. Spawn's little minerals are 500. Ramp's minerals are 16. Yeah, nat don't defense main's ramp, but if wait hatchery's creep grow you can make sunken what defend that ramp. You should build on high dirt. Give me some comments plz.
modified by SiaBBo

small passages...

too narrow, while it is too easy to expo. Maybe you should add another way, like blocking with 64minerals some big ramp to the expo behind the nat, so that when u finished your nat you can use an easier way to atk.

When I was making this map I had to make big ramp there, but I didn't found good ramp there. Well, now I found it. Minerals there are all 40.

If the nat does not defend the main then a hatch at the entrance of the main should at least defend the nat. In your map this is not the case. This map will be a bitch for zerg.