Thank you all for your kind words!
Did you just "undither" the images, or something more? There are some nice gradients.
Yes, It's based on undithered pics, but there is more. First of all different and more colors. Some objects that have the same color in EGA have different colors. Eg on the screen with the dwarfes hut. In EGA most of the tree and the ground have the same color, now they are different. Still need to do something about the brown rocks in this screen and some other screens.
Gradients as you mentioned, a simple one for the sky and something more complicated for the sea at the beach of Tamir. This is incomplete on Genestas island btw. The River is a "pattern" with different colors, my plan is to use palette swapping on the river, which I think will look cool.