It is crazy how much content and how many assets there are for this. I can only imagine from the description that most of this is taken from the larger project mentioned. It was fun to see a fully realized JRPG system in browser, but I didn't get too much into the gameplay.
One thing that might be worth considering, if this is the proof of concept for a larger game, is what is gained by having the visually wandering monsters, rather than the random invisible encounters. I found my self having little dancing and dodging contests to avoid the enemies, which doesn't feel like the kind of behavior you want to reward in a game like this. But who knows!