Alfa Beta Charlie is heavily inspired by The Imitation Game and by the Wisconsin Card Sorting Task. The latter is a psychological test that tries to demonstrate someone's flexibility in learning rules "in the face of changing schedules of reinforcements" .
In Alfa Beta Charlie, your mission is to decode as many symbols as possible by finding its corresponding word (i.e. alfa, beta or charlie). During gameplay, the "pattern" for decoding will change from time to time (i.e. the corresponding word might depend on the symbol's colour while at other times it might depend on its shape). You won't, however, get any signals that this has happened (you have to find the new "pattern" again to decode the symbols).
To win, decode 18 symbols before time runs out!