Well, it's pretty. You're heading in a good direction.

The continental shelves may be bugging you as much from their unnatural uniformity, as for their width. With this production method can you widen some and shrink some? Add they're showing some of the squared-off (octagonned off??) characteristics of mechanically expanded coastlines.

The rivers have way too regular a set of meanders. At continental scale, what you have is somewhat generalized, but you don't want the water simply riccocheting back and forth across a narrow valley. Look at some small-scale maps of rivers, then look at some Google Maps satellite views of the same areas. Too, the meandering is not a uniform characteristic of rivers down their whole length.


Another issue is placement of the rivers. The overall networks are fine - maybe excepting the big southern delta, which may be off, depending on your actual scale. But barely below the center of the whole image, see that rather steep mountain? The river skirting its NW sides isn't down in flattish territory, but rather seems to be running sideways across the slope. Your altitude coloration is vague enough that I only see that effect a few places, but you want to ensure water's not flowing uphill or sideways.

If the texture shown across the oceans is supposed to be seafloor relief, it's overly uniform. At a glance it's OK. Sure, it's nicely crinkled, but it's all the same *degree* of wrinkled. With a real seafloor you get more variation, including seamounts that don't breach the surface, midocean ridges and coastal trenches (thanks to tectonic effects), and some sedimentation directly out from major rivers.

With your combination of roughness and colors I'm not sure what all your intended meaning is - what's exposed rock vs. what's high altitude - which green means what amount of what type of vegetation.

Keep dinking with it - it's a good start!