Super Mario Bros. Alternate Ending is a sad ending from the game Super Mario Bros. If this ending was in this game, the Super Mario series will never exist.
While Mario was fighting Bowser, Luigi was killed by Kamek. Mario then says "NO! Luigi!", then Mario looks at Bowser while being angry and says "You'll pay for this evil Bowser", then Mario tries to defeat Bowser using his fireball attack, but instead, Bowser uses his newly invented Minecraft-Fire gun (Which will cause a prequel to Minecraft) at Mario to turn Mario into the evil Herobrine. Bowser tells Herobrine (formerly Mario) to turn Mushroom World into the Minecraft World. After that, Bowser attempts to team up with Herobrine. But instead, he disagrees teaming up with non-Minecraft things. Then he joins him. Later, they turn the entire planet into kind of chaotic, then leading them to a prequel of Minecraft (Even tough, Minecraft came out 23 1/2 years after Super Mario Bros.).