Aah, you take it too seriously. really, you don't like Spongebob? Pshaw! That's no fun.  Try watching it in a difffernt language,  Korean is particularly humorous.

Don't forget, licensed characters are bread and butter for many working artists. Without the ability to draw to specification and get it right every time, you don't really have a marketable skill.

Actually it's not useless, I've used tilesets with exactly the same format as this in mobile games before. What you're looking at is a 100 px mockup made using the tile set. The visible tiles are: ground tile, dead leaf tile, tiles for the tree line(three of which are visible of a total of ten) two path tiles (continuing section and end), a four piece building tile and two oversize feature tiles(trees). In the basic tileset there is also a forest canopy tile and two variant tiling canopy trees to mix it up a little. What you're confused by is a)the forest treeline which has two variant tiles, one with a bigger tree slightly set back to break up the monotony, the red foliage on the left is the beginning of a corner tile which leads into a vertically aligned section. If you look closely you'll notice the leaves on the ground are actually a 32px tile with a lot of transparency in it repeated a few times. That's always a good trick when using a standard tile size: don't fill every tile right to the edges or you end up with a world made of squares.

Tha's the differennce between working with a programmer who's prepared to put in the effort to actually make a game look nice instead of just throwing some barely rendered trees and mountains randomly on top of a layer of ugly green tiles.

Personally I rarely use dithering in art which is going ot be animated or move around the screen, it just leads to animation"boililng".

oops, and also this is a great example of where you have to break the rules of perspective. In small scale pixel art for games you often have to represent something iconically instead of in true representation. If the trees in this were in proper perspective they'd just be orange blobs, with a couple of pixels of roots at the bottom and they wouldn't read as trees. Also notice the trunks in the treeline which are deliberately smaller to push them back and deemphasise them.

Rocks too high? Well okay, perhaps I got a bit carried away there.