[36C3 CTF] catch the flag (417, misc) / Not so random, eh?
This challenge seemed simple (it was also tagged easy, but not many teams solved it): You have a “game” server you connect to and can move your character around. The game server then tells you whether you fell into a pit, smelled a flag character, were next to a pit or if you “caught” a flag character. All of the source code was available to download, including a docker file for launching your own instance.