3. What responsibilities should game companies have in protecting young users? Should the government step in to enforce those responsibilities?

It's true that there are many youths addicted to games,  but I think it's hard to let game companies take measures, as limiting using time or making the game less appealing is impossible. As for the government,  I think an proper intervention should be taken,  but in a clever and mild way. 

Even if measures should be taken, these measures should focus on property instead of playing time.

The former policy is mild enough to carry out (up to five hours a day in game or one hour a day)