Well, it is not good to do Proof-of-Work in the browser. It's inefficient and people will not keep mining if they have very small chances of getting a block.
I don't know how this could be solved, maybe you should experiment with other forms of ledger consensus that would fit better in a browser environment and at the same would not exclude normal people from participating in benefit of specialized miners.
The network part of this thing is amazing by itself.
I'd double down on the simplicity aspect - for a lot of people cryptocurrency is a weird thing to get into and hard to understand. You guys have taken something as ultra-complex as mining and blockchain and stuck it in the browser, no small task. Make your focus a cryptocurrency for everyone - include demos of how cryptocurrency itself works.