Wow, the first screenshot looks amazing. 1000% better than in black and white. Also the tree looks very good.
But I do not like the green color of the 2nd screenshot. I think it's too bright. Also the brown background-pixels do not look good. The background of the first screenshot is much better.
I am of a different opinion to Harry regarding the second screenshot. The brown pixels in the background tell me this is an underground scene -- if that's the case, then they're doing their job. The green pixels in the foreground (as opposed to a more realistic rocky colour) work well as they stand out from the background without looking ugly or monotonous, but perhaps they could be dulled or be another colour to accommodate more tastes.
I like the second screen some less, because the green color feels a little out of place in my opinion. the overal color is pretty warm (red, yellow, brown) but the green is more towards blue, which makes it a colder color. but still, these screens look awesome!
I wonder... how have you done those water/lava effects? it seems like it has a vertex shader to animate it, am I right?
