I know I'm a bit late, but I just tried out the spectate mode. It's great, but I'd suggest allowing spectators talk in the chat. Perhaps with a [SPECTATOR] tag, and an option where players can choose not to see what spectators say, if spectators get irritating. Something like a /mute command.

Also: I - for some reason - keep getting logged out and then can't log back in again. Not sure if there's anything you can do about that, but I thought I'd mention it anyway. It doesn't give me an error message or anything, just refreshes the page.

Anyway, time to get myself to the top of that leaderboard.