Same feeling here about the demo: sometimes there is not red shape, so should I click correct or incorrect? sometimes the red shape covers two different styles of roof (I don't know if it is one or two buildings), is this correct or incorrect? sometimes the shape covers a very small thing, could be a phone box or kiosk, it's not clear compared to other buildings around, is this correct or incorrect?

I really hope such a project can thrive and be useful though, will check it again after some time!