Visually very impressive as everyone has said. I wish I could pull off that sort of thing myself. There are a number of things that you might want to consider in future though.

The labeling doesn't really mesh with the rest of the map. It looks like a computer overlay. It's also rather hard to read in places due to poor contrast. Labeling is one of the things that really distinguishes a cartographer from a graphic designer or geographer as it is a very specialized skill. Careful label placement, careful adjustment of letter spacing, paths, or even individual letter positioning makes a huge difference in the look of the map. The straight line diagonals and extensive use of broken labels in your map hurt it. Text Along Path, and letter spacing control would help a lot. If your software doesn't support it, you might want to try doing your labelling in Inkscape. It's particularly time consuming, but if you can adjust how you draw the underlying features in order to 'make room' for the labels without relying on halos or garish colours for contrast, that can make the map more of a cohesive whole, rather than a stack of layers (in all honesty, I've only gone this far once).

The road map locator grid really doesn't make sense on this kind of map. It's the kind of thing you need on a road map, where you have a very dense set of named features (roads) that you need to be able to locate purely by name with no other information about location. This map is not like that. It also seems anachronistic for what appears to be a pre-industrial fantasy setting. You may be confusing the locator grid with lat/lon graticules do occur on a wider range of maps, although still not on most of them.

Given the what seems to be significant variation in climate, I'm assuming it's a quite small scale map. If so, the scale bar indicating a fixed linear scale doesn't make sense (and yes, I know someone else said you SHOULD have one) Maps that cover a significant portion of a globe, can't measure straight line distances consistently. You have to stretch, squash, or tear the map in order to flatten it. The compass rose/rhumb lines and the polar terrain at the top make it worse since they say other things about the map that are particularly incompatible with a consistent linear scale, which is what the scale bar says about the map. Different maps preserve different properties of the features they present and these funny things on the map that might seem ornamental like compasses, graticules, and scale bars describe what it is the map is preserving. For a map with the extent this one appears to have to be bearing preserving for the compass, it would have to be in Mercator projection, which means everything gets stretched out as you near the poles.

The marine routes might work if the setting has extremely long fixed ferry routes, or as an indication of effective distance if they are using a relatively fixed speed propulsion system. Either of those seem a bit anachronistic though for a typical fantasy world. Ships vary, and most fantasy worlds have sailing ships that vary significantly with weather and the direction they are travelling. You may again be projecting ideas of modern road maps at much larger scales, which do show ferry routes.

If you want to fill up the 'empty' space of the water, more rhumb lines would work or fantastic creatures, or just let it be. The temptation to 'fill up space' or 'balance things out' really hurts maps. Real maps look just fine with empty space and with unbalanced appearances. Adding stuff 'because you can' is also one of the banes of cartography. Good maps present the information they were designed to present as clearly as possible, and that means not including anything that doesn't need to be there: A population density map shouldn't have a compass rose meant for navigation maps, even if it is bearing preserving. A road map shouldn't have a 'dominant tree species' symbology, even if the map maker has access to that information. Less very much is more.

It's not that any one thing is outright and singularly wrong. It's that the combination of them, particularly with the rest of the map, doesn't make sense. If all you want is a pretty picture that looks like a map then the only criticism that really I'd maintain is the labelling. It looks "off" to me in a way that detracts from the beautiful work underneath but I admit that people who really know about maps are fairly rare and so it's not going to impact that many people who look at it, and there's nothing wrong in making pretty pictures that look like maps if that's what you want to do.