Yeah I know, hours long time, but hear me out. There was no magic balloon, but it eventually turned into a vortex which took her into another dimension.
It was topsy turvy every which way. The ground looked like the sky, the sky seemed to be of a purple texture with cat faces, and no matter where she went, Pinkie Pie would always hear King of Speed from Daytona USA stuck in her head. This had to be Discord's world, but Discord was no where to be seen.
Instead, there was a earth man with black hair, a sweet-looking beard and a blue shirt. He introduced himself as Billy Mays and showed Pinkie Pie his handy dandy light switch, and allowed Pinkie Pie the chance to play with it for $8.95. She flicked it on, and a loud buzzing came through her ears and she woke up.
She was in her bed in Sugarcube Corner. Everything seemed normal…except for the fact that she was in Gummy's body, and as she shared his brain, she knew the meaning of life, which overloaded her mental space and made her faint.
She woke up again in Sugarcube Corner with Fluttershy and Rarity by her bedside. They told her that she had to be taken to the hospital because of what they described as her bizzare, supernatural babblings that started spontaneously the previous day.