There's a great talk by Mark Ferrari about his work: https://youtu.be/aMcJ1Jvtef0
* All the animation is done using color palette cycling (which is very impressive!)
* The scenes were originally made by Mark J Ferrari and ported by the author as a demo for color cycling in HTML5
[0] http://www.effectgames.com/effect/article-Old_School_Color_C...
EDIT: there's another demo page with some more artworks[1], I have to say I find this absolutely stunning.
[1] http://www.effectgames.com/demos/canvascycle/
[0]https://github.com/Slord6/colour-cycle
Dirt cheap and It has some wonderful advancements such as changes specific to time of day!
There's a great talk by Mark Ferrari about his work: https://youtu.be/aMcJ1Jvtef0