Hi, hope you're doing well!
What phone are you using? There might be a bug, and I'd like to fix it.
Here's a screenshot of what it looks like on my iPhone 5: http://destroyer.io/chat-screenshot.png
The chat box should be at the bottom right hand side of the screen.
Let me know and I'll get on it. Thanks!
PS: Just noticed there's another HN thread on Destroyer.io, I had posted one, and had been answering questions, here - https://news.ycombinator.com/item?id=8074934