A major Pokemon Go festival in Chicago to celebrate the one-year anniversary of the virtual game went badly wrong when technical glitches prevented many fans from logging on.

Pokemon Go has launched in a number European countries in the last few days, but the global roll out will take longer.

While Pokémon Go has already generated millions of dollars for developer Niantic and Nintendo, it could always do better. Niantic has revealed that it is looking at the idea of sponsored locations.