By rich I assume you mean detailed like this ?
https://www.google.com/maps/@63.5498...4541168,12.13z
The first thing is the scale.
First, the outline is thick, you could have more details with a smaller one.
Second, if you want more details, you might consider working on a larger file. Your file is 3070 × 2171 pixel in size. If this is the whole world, the map is simply too small to included detailed coastlines.
Lastly, I think the general shapes look good.
Is there a particular reason why the islands appear to be rotating around the center? Is the world a sphere like Earth?