Agent USA is a 1980s educational computer game designed to teach players about state capitals. The game focused around a mutant television set, called the "Fuzzbomb" which had begun infecting United States cities. Agent USA, who could defeat the Fuzzbomb by growing energy crystals, traveled the United States via train, encountering "fuzzed cities" along the way, with mutant inhabitants who would take the Agent's crystals. Agent USA can drop a crystal without anyone else taking one and watch it multiply, since a total of 100 crystals are needed in order to defeat the Fuzzbomb. Source: Wikipedia, "Agent USA," available under the CC-BY-SA License.