Looks good so far. I'm guessing that the part where the rivers get all squirrely on the northern continent's east coast is a swamp...if that is so then bravo on getting your rivers done properly The mountains along the coast might be a tad unrealistic but that's not a real big deal...you could add some land around them so that the transition is not so abrupt or you could back them away from the coast a bit. The part where they form the land bridge is okay as that is to be expected.