The New Super Mario Brothers and Donkey Kong Country Returns both have Super Guide features where, if you die enough times, the game offers to finish the level for you. Just toss your protagonists into the abyss until the game gets the point, and then you're free to run off and poop. You know those crappy parents who will gladly finish their child's homework if the tyke struggles too much? This is the same thing, only slightly less detrimental to humanity.
Don't worry about them using Luigi for the worst part of the game. He's used to it.
Another game, called Bayonetta, streamlines the process even further by including an Automatic mode, perfect for any hardcore gamer who finds "Very Easy" to be the most frustrating thing on the planet. Tell them to turn on Automatic and sit back as the game does literally everything for them. Now you're just ordering your parents to do your homework, which they'll gladly do because otherwise you'll feel bad and that's child abuse now apparently.
"Man, can you believe kids used to LOSE at these things? What a bunch of weenies."
Then there's Ryse, possibly the silliest example of all. It doesn't technically play itself, although it might as well. During the game's quick-time events, if you press the wrong button, or something shiny this way comes and you forget to press any buttons at all, the event is still successful. So maybe your parents didn't do your homework for you, and you bungled every question badly. That's OK, though; the teacher still gave you an A+ so you feel good about yourself.
"Hey, kids, death is inevitable, and there's nothing you can do about it!" -this game