Game designer Mike Mika has shared the inspiring account of how and why he hacked a Donkey Kong game ROM to switch the Mario and Princess characters for his three-year-old daughter. Mika, who has worked on Atari 2600 games before, used the free Tile Layer Pro software to extra sprites from the NES ROM file and replace them with his own art. The process involved not only adjusting the Princess's height to to match Mario's and tweaking the game's color palette, but creating new animation frames for both the Princess (which he named Pauline) and Mario from scratch and without animation tools. The finished result looks flawless and delighted his daughter. You can watch video of Mika's version here, which also includes a link to the file required to alter your own Donkey Kong ROM.