I see your point. KoL is a complete different genre of game, but it's similar in that it looks like it was designed more than a decade ago, just like my game. For niche webgames that offer a little more depth, graphics seem to be far less important. Still, I'd like to invest some time in making it look more professional, if only to be able to show it to people without making excuses.
Also congrats on getting this far with your project, all I have to show for my spare time for the past few years is a reddit account full of sarcastic comments.