I played 무궁화 꽃이 피었습니다, 말뚝박기, 얼음땡, 제로게임, dodgeball with bouncy ball ten years back.

I remember watching MBLAQ playing 만두 (Dumpling) and I think,일,이,칠,팔 (One, two, seven ,eight) 

For the first, everyone stands in a circle, and pinches all their fingers together, holding them out in front of them. Everyone says 만두, 만두, 만두 then the designated speaker yells a number in the five range (0,5,10,15) dependent on the amount of people there ( You cannot yell 40, if there are only 3 people. The highest can be 30. They also have to speak quickly). After everyone says 만두, and the person says the number, they have to either open or close their hands (dependent on them) If the number yelled out, corresponds to the number of open hands (one hand=5, two hands=10). They win, and are removed from the game. This continues until one person is left, who is subjected to whatever penalty was decided at the beginning of the game.

For 일,이,칠,팔, everyone sit /stands in a circle and calls this about five times. In order, they call out numbers (numerically?? lol, in order, 1,2,3,4,5,6,7,8,9 etc) avoiding numbers that have the ones above (일,이,칠,팔) in them. Whovever does so, suffers the penalty.  For more fun, you can clap when that number comes around, and if the person speaks instead of clapping, they suffer (BWAHAHAHA!!!).

Any set of numbers can be used.

Sorry for the poor explanantion.....Hope it helps..

Maybe younger kids are not interested in italki.com. But they are studying english a lot not to be grownup like almost not-good-speaker of senior Koreans ......... Is it right sentence ??

A game i know they play in Korea (although i dont know how often they play it or how popular it is) is 007. It is usually played in larger goups of people and the game is played by one person starting out by drawing a case in the air then they point to someone else which is like giving them the case, this person then becomes the first 0, they then send it to someone else who is the second 0 and then that 0 sends it to another person to become the 7. The seven has the "gun" and will point to the person in the group they want to "shoot" then that person and the people right next to them on either side must raise their hands and if they fail to do so they will get some kind of penalty. I hope this helped answer you question.

Most kids play computer games such as 'League of legend' etc.

It's hard to find play games outdoor because parents don't want to let their children go outside due to danger like kidnapping traffic accident. T_T.....