Some dude has for the last 15 years been recreating the complete Operating System of the X.A.N.A Super computer from Code Lyoko. You play as Jeremy and it's kind of like an RTS, but it's super show accurate to what Jeremy did in the show. The depth this game has requires you to learn over 100 different fucking command lines to run the computer properly. So far the gameplay portion is basically done with a non story challenge mode you can play, rn their still working on building a story to play to go along with it. Probably the most impressive fan game I can even think of desu.
You can also play as Jeremy running around the school away from the computer, so you might actually have to escape a X.A.N.A attack and find your way to the warehouse during the irl sections.