The chair staking game and the football game are random you can't choose if you win or loose!
The flag game chooses a flag, and puts it on the top of the screen and you need to press A button or C button, you have to match the flag on the screen with the same coloured flag that you are holding! but watch out, sometimes they try to trick you!
The benifits of the main games are to raise your skill points so your tama can get a good job when its older!