WARNING: I tried to make this unlike most gaming creepypastas. So I hope there's very few cliches here. This is also my first creepypasta, so please be nice! ^^
There was a male, 16-year old gamer named Zack who recently became a fan of Mario after playing a couple of Wii and Wii U Mario games. He was interested into New Super Mario Bros. U, and waited for the release date to come. When it finally did, he made it to the store called John's Game Castle, and all the kids knew and loved John. Zack was also good friends with him. When John held out the game inside the case, there wasn't anything suspicious or wrong with it. He bought it, took it home and put it into his Wii U. Little did he know that it'd be his ticket to a living hell...
After the splash screen ended, it faded to black longer for 10 seconds, and within this, the game flashed a realistic picture of Bowser. It made Zack jump a little, but he moved on. There was no intro. It just skipped to the level selection screen. Upon entering World 1-1, there was no HUD. No enemies, no coins, no blocks. Not even music(aside of faint, monstrous deep breathing). It was just Mario with the normal backdrop. There wasn't any changes in the level design. When Mario was halfway done with the level, there was a dark red pipe. Zack made Mario go down the pipe, and it was Bowser's corridor. Fortunately, there was power-ups. When Mario made it to Bowser, he was slightly bigger. He also had a more threatening look on his face, and said, in a deep, terrifying voice: "My revenge has finally come." He did his roar, only extremely loud. Zack was very scared by this point, but still moved on and fought Bowser. The Koopa King was also far stronger and way faster. There was no bridge axe or button. The Fire Flower didn't hurt him. Eventually Mario died, and Zack heard deep laughter. It sounded so clear that it sounded like Bowser was behind him. The game then froze.
Zack then restarted the game, and the title screen was different. The backdrop was World 8, and Bowser was in the title screen. His skin was darker and more reddish, and his eyes were pure white. The music sounded like Giygas. Instead of New Super Mario Bros. U, the title said "Bowser's Vengeance". Zack was very horrified by this point but continued. World 1-1's title was now called "No Escape". Mario looked horrified and broke the fourth wall, begging to get out of this mess. The backdrop was World 8 again, and Giygas' music was playing again. Blocks and coins were rare and there was a onslaught of enemies. It was a extremely difficult level for Zack. After a while he finally beat the level. The flagpole was color inverted. After Mario slid down the flagpole, there was no castle. Bowser then suddenly appeared and broke Mario's neck, with (Sorry, Mutahar, but...) small drips of blood leaking out of the poor plumber's mouth. It wasn't hyperrealistic, it was designed like the rest of the game, with bad graphics. Bowser then threw Mario out of the screen and horrific gory sounds were heard, although not seen. Mario was heard screaming. When it stopped, Bowser looked at Zack, and said: "You couldn't win..." Then a picture appeared. It was Bowser standing above the Mushroom Kingdom, except that it was full of fire. Faint screams were heard and Bowser was heard chuckling with a manical smile on his face. The screen then faded to black and it showed "Game over". Zack was horrified, and was about to turn off the Wii U, until...
...the same picture of Bowser after the splash screen appeared, only color inverted, shaking horribly and Bowser's loud roar from the battle was heard, only even louder. It was so violent that the TV screen exploded, with shards flying into Zack's body, one into his heart. It also knocked Zack against the wall. The last thing Zack saw was Bowser's shadow above him. Then he was gone.
His family, neighbors and doctors thought that he died from a heart attack. They couldn't see the glass or the glass wounds, they were invisible to them. Zack was then cremated, with his ashes planned to be kept. From the crackling fire it was almost as if everyone who was there saw a flash of Bowser's shadow and heard demonically deep laughter...
I hope you enjoyed it, and I hope I didn't add too many cliches or blood. I had fun making this. And once again, this is my first creepypasta, so please be constructive. ^^