So, Super Mario Bros. is nearing its 30th year in existence, so you'd think that we would have found every secret it harbors by now, right? Well, someone went and found a glitch that a lot of us have managed to overlook--and even managed to capture some video of it.
Retrocollect has posted an explanation about the glitch, and how it can score you infinite one-ups midway through the game. The video below also shows the glitch in action as well.
"First, you must first take player one's Mario to the second level of the game and throw away your first life. With Luigi taking over, player two must traverse all the way to World 5-2 and find the hidden beanstalk block halfway through the stage. Once there, Luigi must start climbing the vines, however, he must await - and take on the chin - an incoming projectile from one of the Hammer Bros. Upon being hit, once player one resumes control of Mario, the beanstalk from World 5-2 will start growing in World 1-2, providing all you need to infinitely kick shells for unlimited bonuses."
We haven't tested the glitch out ourselves just yet, but it looks legitimate.