The category is pretty self-explanatory. You have to beat all of the games as fast as possible. I think this would be a great challenge since the runs are way longer and you have to learn every game.

(I think it would be better if it also has the sub-categories "1P any%, 2P any%, 1P 100% and 2P 100%.)

2 years late but Multiple Fireboy and Watergirl games now exists with said categories lol.