Don't even get me started on Mother 3...
Well, spoilers, since you clearly aren't going to play the game anyway, DD...
Lucas' mother dies during the first chapter of the game because she gets stabbed in the heart by a giant dinosaur thing's claw, his dad finds out, goes on a depressive rampage in a fit of rage, incapacitating a few passersby, and is thrown in jail, as his son watches, traumatized. Lucas' brother goes missing, and is found in a canyon later, thought to be dead. More depression ensues. Then there's a tyrannical dictator, Porky, who builds his own "utopian" society not that far off from being compared to the Nazi rule of Germany during WWII. And his greatest general that Lucas must face? His own brother, who was cybernetically brought back to life to be a killing machine. Lucas has to kill his own brother, or else he will be killed by him. And you know what? He chooses not to. Then Claus tries to kill him by shooting a gigantic bolt of lightning at Lucas, which gets reflected back at him due to Lucas' Franklin Badge. He killed himself. And then as Lucas is holding his dying brother, he dies in his arms, for God's sake. And then the world pretty much blows up.
You know, for kids.