I made
this post a while back to show that it is indeed possible to add new terrain palettes.
RattleBattle wrote:add another Terrain to mix with the Original one.
I'm not sure what you meant about this. Are you referring to different tile types, as in one that slows Kongs down when they run on it, or new types of scenery, such as porting the mill level type from DKC3 to DKC? Either way, both of these would be difficult to implement. (Not impossible, though)