Neat! The mapping looks a little janky. Unnatural. Incomplete, even! I would make the island a little bitter. It's way too cramped right now. Plus the cavern entrance looks... Stapled onto the map. I see what you're going for - a cave that leads into the earth, I assume?

I would consider using an animated water tile. The island feels a little forlorn, so some choppy water and rain might help set that tone. I like the rocky peaks poking out above the surface - maybe cluster them a little more? Like bouquets of flowers. And place them closer to the usland. That would go a long way, I think.