We just had a very successful hackathon where I work. About 10 separate teams coded basically overnight and the results I think surprised everybody. There was something about the energy and, well, slight insanity of staying up all night just to see if we could deliver a full product in under 20 hours...there was definitely something to it. The demo the next morning, where all the teams showed what they had done was pretty dang impressive. A few of the delivered results will likely become real products.
So from my perspective, the energy and "field day" attitude of a hackathon creates an urgency and focus that's feels like the early days of a startup, where sheer adrenaline and excitement creates more productive mental state and team effort I think. It's a thing, I tell you.