In the UK official attempts to ban Manhunt 2 failed
Europe's game rating system must be strengthened to protect children from harm says the European Commission.
The recommendation came in a survey of how Pan European Game Information (Pegi) is implemented in member states.
The survey revealed that some nations are doing nothing to enforce the age limits on games drawn up by Pegi.
The Commission called for a code of conduct to be drawn up so retailers across Europe are aware of their responsibilities.
The survey was carried out by the Commission in response to a request from the Council of the European Union for more information about national differences in game rating enforcement.
The survey found that 20 states currently use Pegi and back up its recommendations on who should play particular games by different means.
Pegi ratings describe the content of a game and give information about violence, bad language, sexual content and drug use.
The survey said Germany and Lithuania were the only countries with specific laws governing how all games are sold. Malta has enacted broader laws on the same of games and a further 15 have laws that ban the sale of games that are potentially harmful to minors.
Four nations, Cyprus, Luxembourg, Romania and Slovenia, have no laws relating to the sale of harmful games.
"Our clear message today is that industry and national authorities must go further to ensure that all parents have the power to make the right decisions for themselves and their child," said Meglena Kuneva, the EU consumer commissioner.
Game ratings in the UK have been in the news because of official efforts to ban the game Manhunt 2 and because of the Byron Review which looked at the risks posed to children by harmful content in games or online.
The Commission called on member states to integrate Pegi more deeply into national systems and provide funds to raise awareness.
Work also needed to be done on novel systems that can be used to verify the age of anyone buying a game that could prove harmful.
Shops that sell games should also sign up to a code of conduct that the Commission wants drawn up by 2010.