Not bad... infact I liked it
First off good animation, made it nice and short... though you could of made it funny and made it longer.
Umm... howabout hovercrafts? Though I think there is a circle somewhere involved in the motor of a airblower machine... as well as a car engine, and was her steering wheel still a cirlce?
Though if we never had circles how far would we have evoled anyways? I think you should of thought more about this first... but it is interesting and good anmation... make a part 2 and 3 and 4 and etc etc etc