Enjoy it while it lasts. It sounds pessimistic of me to say but once the company catches wind of you enjoying yourself it'll be taken away. They'll realize after some careful spreadsheet analysis that participation in this hackathon is an all time high. You know it's because you guys can do what you want. They don't. They just see the distilled numbers. So, the C-levels will order everyone to instead work on a work-related project with a mandatory demo (for "fun" time constraints!) and everyone will be miserable. Participation will drop, and then it will become a routine where they get all the engineers to do a song and dance once a year for them. That's all "demos" are, anyway. Of course that'll be sold as "giving the engineers an opportunity to improve their speaking skills for conferences" or some trite bullshit typical of sub-zero IQ C-levels.

I dont participate in any kind of hackathon or after work in-office "fun" event because they almost always turn into extra work hours. If you want to hang out you can find me at the bar.