Posting a roguelike I made a few months ago: http://pubby.github.io/hejickle.html
I gave this a try (although not sure why since I rarely play classic roguelikes and rarely play NES games). Anyway it's nicely polished and looks like some serious work went into it. (The FOV system looked pretty sophisticated, so if you're writing machine code or something like that, nice.)
Some comments:
The online emulator was too slow on my computer. As mentioned above, I don't really play NES games, but I do have RetroArch installed so I gave it a try with some emulators in that. bnes did not work for me at all. FCEUmm mostly worked but with slightly glitchy audio. Is there an emulator that you recommend?
Suggestion (UI): When using select to inspect in the start menu and pressing B, it would be nice for the menu selection to return to what it was before I pressed select. Currently, it always returns to the first item of the list (Armory).
Bug (UI): The select info for Armory and Log is swapped. (I mean, the info for Log shows when you get help for Armory, and vice versa.)
The only spell I tried was Fire Breath, and it has a fun & satisfying animation.
Overall, the level of challenge felt a bit low. I died in the Dungeons on my first attempt but only because I couldn't figure out what the A button was in my emulator _and_ forgot to look at the start menu, and made it halfway through anyway. On second attempt (with A button located and start menu remembered) I beat Dungeons & Sewers, then saved because I was getting a bit bored. I think part of the issue is that the Dungeons enemies were not very differentiated: in every case I just bump them until they die. The Sewers enemies were better in that way: using my Fire Breath to take out the fire-vulnerable Tarantulas at range was interesting, and Slimes definitely feel like a different enemy because of the splitting.
Also, this is not very important, but it would be nice to have a select info explanation of how damage, armor, missing, etc. work. (I couldn't find one in-game if there is one already.) I tried to guess it from looking at the log but didn't have much idea. That makes it hard to value the +1 AC upgrades from the shop. Sound is something else that could have used a little explanation. It has a quite prominent place in the game, so it must be important, but it wasn't clear to me what it's doing. (I mean, I guess it wakes guys up, but things like range, % chance to wake up, etc., were unclear.) EDIT: I forgot to mention that what puzzled me most was speed. Like, clearly faster guys can sometimes move twice for one of my moves, and sometimes I can make two moves for a slower guy's one move, but I had no clue when to expect this.
Anyway, I feel a bit silly since I'm just commenting on the surface level as a game, and not on the impressive aspect of doing it as NES-compatible, but I don't know anything about NES development so I don't have much to say about that.