The map itself: not bad. Nice geographical layout, no major problems I could see. The islands on the lower left side could use a little reworking... this left-squiggle-tail part obviously came from the drawing, not from design.
The style: you said it yourself, lines and triangles, easy stuff. Not bad for a sketch, for a polished result you'd need to be a little more precise in your lines. The spaghetti-treetop-little-wiggly-lines might give a better result if you keep the horizontal.
The background: well, it looks... a little wierd. The greenish colour is quite uncommon, though not bad. You might want to try some other, more regular paper colours though. The dark spots are to strong for this map... they overwhelm your drawing. And at the border, you should definitly get rid of the free-floating parts.