Great concept, very different from a lot of the stuff on here, in a good way!
My main criticism is that the timing seems maybe a little too tight, there are plenty of times it looks like I should have hit it at the right time but had my score reset anyway.
Also from a design point of view if you have to hit the button when all the lines are matched up, and this happens whenever the centre ring matches up, is there even a need for the other rings to begin with? I would suggest maybe having the timing of each ring offset and then gaining more points for the faster outer rings than the slower middle ring.