/ic/ - Artwork/Critique

Requesting advice on how this could look better and stupid mistakes pointed out.

Some of my own thoughts:
> Only indicator of distance to the other islands is the size of objects, could add sth like clouds/haze in between or make them more blue-ish
> Faulty perspective (vertical stuff being vertical despite looking down a bit)
> Corn looks flat and boring, not sure what to do about it except adding some plants at the edge
> Could have more and bolder shades
> Need to learn drawing people, person and cat are mostly traced from photos I took
> Must be more I'm missing

Thanks in advance.