A Cybersecurity Day event.
Official URL: https://csd.ctf.platypwnies.de/
The year is 2231. The solar system is entirely occupied by alien invaders. Well, not entirely... One small planet of indomitable humans still holds out against the invaders. And life is not easy for the alien occupiers who have established bases on several planets and moons...
Come and join us on-site here: https://www.openstreetmap.de/karte.html?zoom=18&lat=52.39372&lon=13.13326&layers=B00TT