This does look awesome! Great thought to include the swirls of algae in the ocean! Also, great use of the blue tinting to show distance under the atmosphere. I just have two comments for you - and hopefully we'll see more maps like this from you in the future.

First, remember that the algae/sediment swirls are going to be related to where the rivers flow out into the ocean. (I could imagine some rivers under that tree canopy.)

Second, I can't quite tell where the Sun is supposed to be. The specular reflection off the ocean and relief shading on the terrain makes it seem like the Sun is over the viewer's left shoulder. But the way the atmosphere is lit up with a lens flare, I expect the Sun to be just behind the limb of the planet at the top. I think to make the atmosphere look less like it's sunrise/set, it should be more blue and without the flare. But a sunset perspective would sure look interesting.

Great work, regardless. I'd say your test was successful.