The blocky stuff is middle-distant terrain. I made it to look like the foreground terrain. I reduced the tan foreground tile to 60% opacity and varied the height. I know it's common practice to ignore the blocky appearance of the foreground when making distant terrain, but I made it look the same. This is partly due to the fact that Fredrik Andersson's Rough Sea Landscape tileset is being used in the level it's for. RSL's distant ground mimics the close ground, it's 100% pixel art, and it's simplistic. In that light, I probably have too much detail in the trees and rocks. RSL is also to blame for the weird highlighting on the collision areas. Or maybe, I'm to blame for putting an outline meant for rocks on grassy soil. Guess I'll take another crack at it after I get more feedback.
By the way, thanks for the praise Minmay. I know you don't give that out lightly.