The main base is too small. Push it back into the corner to create more space.



The route into the natural is quite narrow. This will be a real pain for zergs trying to fight against forcefields, mines, tanks, colossus. I recommend clear out the plant doodads against the main and widen the path up to the main cliff there, and/or widen the ramps to make it more open.



The little wiggly holes in the ground in front of some of the lowground bases, I don't think those are required. The layout already has a lot of chokepoints and narrow places. If anything, get rid of those and replace them with thinner/smaller doodad obstructions. (You can paint the no-pathing in by hand to be precise and use doodads with footprint turned off just for a visual indicator.) Even just LosB instead would be fine. This map doesn't have any wide open areas at the moment.



The towers are very defensive. Since that 3rd base is already relatively easy, I'm not sure it's good to have a tower right in front of it. This map would definitely be just fine with no towers.



Other than those nitpicks, this is an interesting map with a good layout concept. Have you thought about gold bases in the center?