Definitely not what I expected going in and a surprising twist, that I think has more underneath it. I'm not quite sure. Anyway the overall loop was interesting and the switching keys definitely added a bit of urgency to what you're doing. Though I do have to say sometimes it was a bit hard to know which key was which when they just suddenly changed, I very much preferred when it flashed in and out while changing which helped indicate that I needed to check the keys again.
An interesting concept to say the least though, definitely a nice time to just see what was behind the curtain and get pleasantly surprised.