Story
The main character is a follower of Ryo Hazuki and is guided by him to explore, attempt quests, and grow strong through battle. Characters from other Shenmue games make appearances as well, and much of the original Shenmue plot is retold.
Gameplay
Gameplay in Shenmue is diverse; while most of the game is spent walking around the Japanese locations in a third-person ‘chase cam’ mode (talking to people, searching for things, and so forth), it is interspersed with many minigames, including forklift and motorcycle races, bar fights, chases down crowded alleys, full versions of Sega arcade games Space Harrier and Hang-On (both originally programmed by Shenmue creator and director, Yu Suzuki), dart games, and fighting sequences.
Development
Shenmue City was first conceived when Yu Suzuki noted the popularity of Mafia Wars, a social game designed for mobile phones. Suzuki formed a plan that if the game was a success, its popularity could be leveraged to make a game to conclude the Shenmue series. Suzuki stated in an interview with Famitsu that he wanted to explore the series without very expensive graphics or sound elements like the original game. The games beta began on September 21, 2010 on the Yahoo! Japan and Japanese phone carrier DeNA’s Yahoo! Mobage network. On October 7, 2010, Shenmue City was also announced for the PC as a browser-based game with a winter 2010 release date, but was never released. The game shut down on December 26, 2011.
Source: Wikipedia: Shenmue City