Game developer and early contender for father of the year Mike Mika hacked Donkey Kong so his 3-year-old daughter could play as Pauline, the damsel-in-distress character, and rescue Mario. In the Youtube post picked up by Polygon (h/t Atlantic), Mika wrote:
"Two days ago, she asked me if she could play as the girl and save Mario. She's played as Princess Toadstool in Super Mario Bros. 2 and naturally just assumed she could do the same in Donkey Kong. I told her we couldn't in that particular Mario game, she seemed really bummed out by that. So what else am I supposed to do? Now I'm up at midnight hacking the ROM, replacing Mario with Pauline."