Alright, lets see. The rivers seems to be wrong. Rivers are basically rainwater and water from glaciers. They start from a high (mountains, highland) from several small connected flows, and usually finds the most easy way towards the ocean. It's very rare that a river split up into two rivers. It's more common that two rivers merge into one river.

I would have remade the rivers completely. Think that they should start from the mountains, and find their way between hills and canyons towards the ocean. Also, if the above is a world map, then the current rivers are veeeeeery wide/large.
I'm not an expert, but regarding the mountains, they are (often) created when two landmasses (continents) collide.

If you look at the left continent, at the lowest half-island just above the southern continent, then the mountains are placed like they are crossing the land. This is not impossible, but I think it would be more likely if they I would go with mountains that follow the shape of the land. Think like this. The land actually starts from the very bottom from the ocean and emerges up, up up until it's over the waterline. Then it continues upward to hills and finally mountains.

Hope it helps a bit