Two things immediately jump out at me - you need English localization, and your carousel is currently broken (no matter which touchable button I select, the text is always for the car button - running Chrome on OSX.)
As for the idea: I think it's quite neat, I think physical things people have to deal with 'in the real world' work better for behaviour modification than just notifactions which are easy to dismiss.
Is this out 'in the wild' yet?