Oh wow! That is a really useful tool! Thanks for showing me it. And thank you very much for the kind words I had a hard time not letting the trees become an indiscernible pixel mess.  =)

I think that the number of colors could be greatly reduced. I order to help you in this process, you could use the 'Image Specs Tool' available in the 'Features' menu of the PixelJoint site to get some statistics about the image:

http://wouterpleizier.nl/pj/index.php?input=http%3A%2F%2Fpixeljoint.com%2Ffiles%2Ficons%2Ffull%2Foverworldfinal__r1425694591.png

As you can see, many colors are seldom used and some of them are very close to each others.

By the way, nice work on the pine forest.

Thank you guys!  Its always so nerve wrecking to post my art online. This is the only community that I have ever been able to actually hit the "Submit" button on. 

Incredible trees!  I like the variety and readability of them especially.

Nice font!