It seems that it's only 2.5D though. Have you considered making it truly 3D somehow? There's a surprisingly large amount of extra space you gain with that third dimension.
Also, fun idea: what if the island evolved over time? Like every time you visit, trees grow a bit and some new trees grow next to them, so eventually you get a forest, etc. I wonder what the implications of this would be to remembering things? Would the constant change help, or no?