Then why don't you just scale down the mountains a bit? Don't know how difficult that would be, but maybe you could redraw them in GIMP and resize them? I'm sure there is a function for that somewhere... I haven't found it with a quick look, but i'm sure there is.
A second thing: There seems to be a river running from coast to coast big southern isle (or peninsula? hard to see...). Thats impossible, as far as i know, except if it's a canal. But then that's a very strange route.
Edit: Aaand some other river issues:
- the second isle from the left: Rivers don't split and rejoin later - at least not for such long distances. Small isles or braided rivers, yes, but not such big ones.
- the "donut-shaped" isle in the middle: a lake shoudn't have more than one surface outflow. And again, the western river is splitting up.
Aside from that, i think the map doesn't look too bad. Maybe you could give your continents some texture like the sea (a different one, of course), i think that would look good also.