There are plenty of "how to design a robot" tutorials out there; this is not one of them. Why is this one different? Because the author, GastonLagaffe, doesn't want to tell you what to do, as he doesn't want to limit your creativity. :) His personal goals for this robot were for it to be small, autonomous, cheap, easy to solder, easy to program, with plenty of holes, and swarm capable, and although the journey to get from concept to implementation took him 12 months, he learned a lot along the way.
So if you want to make a robot, why not dream big as you read about how Gaston took what started as a small wish and made it a reality, Gaston-style. To see his journey, check out this HelveKit Robot Design Journey on Instructables. You may smile as you see his approach and decide you would have done it differently, but that's exactly what Gaston would want you to do!