Contrast problems and grid-y aesthetics too strong
Some people might like that sort of aesthetic, the grid-y block-y world, and that's almighty fine, but the contrast between the lines and
the block's color is way too great, so it sorts of "popup" in the eye, and that is a distressing view. Same thing for the leaf blocks.
It could look a thousand times better if the outline of the grass block's top werent so dark and lighter like its content.
And the tree leaf blocks look unnatural, it looks like a mineral, but I dig the artistic look you gave them, just reduce the contrast too and it will be all good!