My first attempt at making NES style dungeons less boring looking. Please be easy on me; I'm still very new to this and it takes me upwards of 20 minutes just to build a single room in some cases. I promise the room designs will start becoming less symmetrical and more interesting as time goes on. This is honestly the first time I have strayed from just using the 12x7 NES style dungeon rooms, so I'm not going to be that great. Obviously, the map is not quite complete. I just want to know if I'm going on the right track or not. I wish there was a less tedious way to do this.
Oh I can beat that. I've spent a few days dealing with single rooms.
Fortunately, those are the odd exception, not the standard process. Admittedly, they took so long because I had to make new tiles for some of them. The nice part about not actually making a quest is that there's no quality anticipation - people just need functional tiles and sample test rooms to see how they're used. It's just that, every time I'd try different room designs, I'd realize I need more tiles to make them work.
But, as for yours, I think you're off to a good start. Keep in mind, most games start you out with simple layouts and basic gameplay then progress into into more complex layouts and harder gameplay, so your learning curve can complement your quest's progress. You shouldn't want to unleash every single design technique and gameplay gimmick in your first dungeon, although you do need to at least make a good first impression, and so far you're clearly indicating non-standard room design will be the standard.
Regarding the actual layout, you've got a nice balance of variety so far. Each room has its own little thing to make it unique, but there's enough consistency that it doesn't look like a grab-bag layout-options demo. FIlling the open floor spaces with different-colored tiles is a good idea too. You have to watch out for those upper-level brick tiles though. In the map room on the right, you've got them used properly - on top of a full-height wall. But in the room directly up from the entrance, you don't have the upper-level wall tiles on the part that protrudes down in the middle, so it looks like the room height goes from 2 tiles to 1 tile high. The way you did it in the room to the right of that looks fine - the rectangle in the middle of the room is an even 1-tile height all the way around, while the rest of the room is 2 tiles high. Similarly in the upper 2 rooms, those corners aren't using the upper corner tiles - the ceiling bricks just hang over what should be the corner instead. It can look a little sloppy, especially if it keeps recurring, so those are good details to pay attention to.
The map location is good, but I wonder about the compass - and if you really need it at all. I mean, you're forced right below the boss door as soon as you enter, so anybody should know they're going straight back there to finish the map. Unless you're using the compass for some other purpose, like how FITS2 made it chime every time you entered a room with an item, it seems like it would only confirm what people already know from the start. Perhaps, to that extent, you don't necessarily need to use the boss key to open the boss room directly, but rather a full dungeon finale segment that ultimately ends in facing the boss.
Now, about the tedium... please, please tell me you're not using the default dungeon tile arrangement that comes with the standard "new quest" file. That's the closest thing to a trash heap I've ever come across in game file organization (sorry to whoever put it together, because I vaguely see the pattern in the arrangement, but it's true). The first thing I did when starting a new classic tileset is rearrange that mess into something actually useful. But more than that, you need to assemble some aliases if you want the tedium of freeform dungeon design to go away. When you can plunk down large chunks of walls, entire corners, doors and the like, things like this can get exceptionally quick to do. Additionally, I see those quasi-diagonal corners in your upper 2 rooms - you might want to look into this tile pack if you want the additional variety that true diagonal walls can add to your layouts. And, if you want to go even more advanced, give this one a try too. (And, if you want to go super-advanced, wait a few months for my absurdly-expanded classic-tiles pack 
)
