Terrific fun. The early prototype I wasn't quite seeing the vision, but with the burning keys, small and large keys (and big improvements to the interface), I get it now! I'm really impressed by the balance and pacing--it always felt like it was giving me just barely what I needed at the right moment, while also feeling like I could always have done better if I'd been a little more strategic. I won on the second try (after having just 1 key left several times!)