Idly Tower: Kingdom Rush

Yeah, so, at about 1pm a couple of people sent me a link to Kingdom Rush, a polished and artfully constructed browser-based tower defence game, and I've only just managed to tear away my mesmerised eyes from the screen to scribble something about it. I don't know what it is about the TD formula, but I find it unspeakably compelling. That's got to be wrong. Right? Anyway.