Agreed about the leaves, they're distractingly fast.
I don't think you need a line for the walkable surface, the grass isn't particularly misleading. Having the floor this way adds some depth to the image. I'd even consider having the platforms set up that way too, so that the feet are never perfectly aligned with the upper edge.
Consider making the coins spin. That's a much more noticeable animation than a little shine, since it changes their silhouette.
It looks like you didn't really consider tiles while making your mockup. I recommend keeping the tile grid visible even that early on and aligning things like platforms to it, it saves a lot of time later on when you're making tiles.
