1) Include all Games (USA, UK, etc) on the "Front Page". Many users don't realize that are others areas if scroll down.
2) Allow the users to change the image. Especially if the image is of poor quality.
3) Allow the user to select a region of interest. (ie NYC, Paris, your home city, province)
4) Keeping adding more regions (ie Canada)
5) New Game: Distance away. Click on the map. It will tell you how far you are away. Keep clicking on the map until you hit the mark. You can also use it with compass directions.
6) Keep a record of all locations, if a user want to explore the area after the game