Steam Greenlight banner can be divided into 4 areas: background, illuminated planet, text, information about the project. You can create each of them in Manga Maker Comipo. Take a closer look at the background. It is not uniformly gray, has colored patches in the upper right and lower left corners.

You need to fill the background with #181C1F color (24 red, 28 green, 31 blue). Place a spheres as shown in the figure above. Remove 3D-stroke, put a blur: Blur = 50. Red sphere colors:

Green sphere:

Result:

Now you can add the planet. This is a sphere, decorate it in the yellow-green:

Duplicate the sphere, move lower one to some pixels left-top and add Blur = 5. Than paint top one into the color of the panel:

Result:

Now add a glowing flare to planet. To do this, add a sphere and deform it, as shown below:

Add a Blur = 33 to new sphere, and the planet is getting ready:

Banner text:

In this case font is also very important, as in the case of the Amazon logo. Fortunately, bold Arial font similar to the original. To get the spacing between letters in the “STEAM” word you can simply add spaces after each letter.

Add a picture of the project and obtain the final version of the banner:

Good luck on the green light!