In 1937, out of a job and eager to see his own posters on London's billboards, he bought 70 copies of the journal Art & Industry, which featured a double-page spread of his designs, and sent them to prospective clients, including the General Post Office, Shell and London Transport. Within a few months, Frank Pick, the head of the London Underground, who had commissioned the struck-through roundel that is still the symbol of the Tube network today and Harry Beck's "circuit board" Tube map, had commissioned Games for his first poster. Eighteen more would follow. 

Two of the early designs are elegant examples of Games's battle cry, "Maximum meaning, minimum means." They were intended for a campaign to encourage Underground users to visit London's cultural attractions. In one, for concerts, ballet and the opera, the Tube roundel has been turned into a treble clef. In the other, for galleries, exhibitions and museums, the roundel has become an artist's palette. 

The most successful of his designs delighted both the London Transport board and the public. Responding to a request for "a gay, colourful and light-hearted poster" for London Zoo, Games came up with a tiger built up from the bars and circles of the Tube insignia. A set of sketches of giraffes, leopards and zebras — all animals with graphic markings — shows how Games experimented until deciding on a tiger whose tail looks like the last few stops at the end of a Tube line. A socialist, he liked the idea of designing for everyone — hot commuters and cheerful day trippers — rather than an elite of art world patrons.