My kids love this online game. It is Tag Team from CBBC. There are 5 games in all. Playing each game will unlock the other games and enable the team leader from the game to be tagged for the other games. I personally find only 2 of the games out of the 5 enjoyable. (Psst.... mummy usually gets to try out the games first to decide on its suitability and fun ratio. ;) )
They are the bowling game called Rollin' Bowlin' Shirley which releases Shaun the Sheep for tagging once you win all the levels. The other one is the clean up game called Tracy Beaker Cleans Up. Once you win all the levels, you can get Shirley to help out in the other games.
At the moment this is their 2nd or 3rd favourite online game coming after Toy Story Games and Ben 10 Games.
Coming soon: Downloadable free Online Chinese Games for Kids