The world of Mario is amazingly happy. There's so many shiny, happy colours, stars, mushrooms, little games of running around and getting stuff. I love Mario Kart and Mario Party so much it's kind of ridiculous. Playing a mini-game of seeing who can dust furniture the fastest? Yes please. Running around in a little vehicle on a cupcake collecting stars? I'll take two, thank you.
There's no violence or anger - there's just little dudes running around collecting points and things. Sometimes you get bonked on the head and a little circle of stars dances around. If that's the worst thing to happen to you in a day, that's pretty fucking awesome.