As someone who has played a decent amount of RotMG, it's OK. A lot of the differences are whatever, though I don't really care for the tall 3D objects. Even with the behind-the-wall glow, it's a bit annoying how much it can obstruct, especially 3+ tiles tall. Not sure if you're planning to make it more than a clone, but regardless it seems like a good base.
Also A+ servers, better than the real thing.