That you were able to use Python to define and train the network in so few lines of code, with no prior knowledge and a 2-day deadline, sounds fairly successful

That you were able to use Python to define and train the network in so few lines of code, with no prior knowledge and a 2-day deadline, sounds fairly successful to me. I think a hackathon will inevitably favor quick copy-pasting, gluing APIs together, and utilizing tools you're familiar with - as opposed to being a good place for beginners to build an understanding of the fundamentals.