it's interesting but two things come to mind. Viewing it on this site makes it seem like it's great, but what about in context? If i came across that, I'm forced to think more than a capthca, just since it's so different and unexpected (maybe that goes away if it's very widespread). Also, it looks like an annoying banner ad game from orbitz or something of years back - that might make me avoid it, ignore or just not trust it.
in context we get about 40%-60% higher conversion rate depending on the use case and have over a 95% success rate. we have a lightbox mode that makes it really apparent what you are doing and only has you attempt a captcha after you submit and the form is validated.
