I hate Jigglypuff. I don’t know why-I never have-but I do. Maybe it’s the pink color of its fur, maybe it’s the design in general. Or the song. Jigglypuff’s song always made me feel annoyed. Always. It was either creepy or overly sweet to me. Anyways, I was once playing my Pokemon Leaf Green game and there it was-that stupid, pink, fat abomination, back to ruin my day. I groaned inwardly and used my Squirtle to catch it-my friend had told me it was useful, so I guess I could give the stupid thing a shot. For some reason, I never got over how much I hated it-that stupid Jigglypuff never grew on me. So I traded it to my friend for a Haunter, which evolved into my favorite Pokemon-Gengar-after trade. He’d nicknamed it what a wanted, even-Gengi. I smiled and began to train it up. I soon forgot about the trade, and was merrily playing through the game, Once I completed it, my friend told me he wanted to trade. I said yes, not knowing what he had put up for trade. My heat sank when I saw what it was-that wretched, sugary sweet Jigglypuff. Frustrated, I traded him a Raticate so he could fill his Pokedex, then gave the dumb puffball it’s worthy spot at the back of my team when I fought a wild Pokemon. For some reason, my trainer sent out Jigglypuff. I choked back a scream of horror. Its sprite was a sickly kind of pink, much paler than before, and its eyes were a saturated gray. Its cry was all static, and my friend had named it. It said; ‘Trainer ASH sent out PAINE’. Ha, ha; very funny. He must’ve hacked it-he was always playing practical jokes on me. I rolled my eyes and made it use Pound. Instead of obeying me, its sprite began to shake, and the text at the bottom of the screen said; ‘PAINE wants to SING.’ The enemy Rattatta took no damage, and used Tail Whip. Getting even more annoyed, I tried again. ‘PAINE is trying to SING. PAINE can’t SING. PAINE is trying to SING. PAINE can’t SING.’ It repeated this over and over, until I finally selected SING. ‘PAINE can’t SING anymore. PAINE used FLAIL.’ The Jigglypuff’s sprite bounced around the screen wildly. It damaged itself, as if it were confused. ‘PAINE can’t SING anymore. PAINE can’t SING anymore. PAINE can’t SING anymore.’ The text continued to repeat, until the battle ended suddenly. ‘PAINE can’t SING anymore. PAINE can’t SING anymore.’ What is this, a guilt trip? I wondered, glaring at the screen as I made my character walk to the Trade Center so I could trade the stupid thing back. More text appeared ‘PAINE wants to SING.’ No duh, you told me that already. I thought, growing even more annoyed as I made my way to the center. ‘PAINE wants you to give it your SING.’ Say what now? I blinked, confused. ‘PAINE wants you to SING. PAINE wants to SING. PAINE can’t SING.’ My stupid friend-he always hacks his games. I sighed and ignored the text. When I tried to offer up the Jigglypuff for trade, text appeared ‘PAINE can’t leave you unless you SING.’ My god; my stupid friend! I sighed in exasperation once more and pressed A. ‘PAINE can’t SING.’ It repeated itself over and over again, until I finally shut off the game. When I turned on my Explorers of Sky game after taking out the Game Boy advance cartridge, something was wrong. I wasn’t a Totodile-I was a Jigglypuff.
And my name was PAINE. I watched in horror as text appeared in the text box..
‘PAINE wants to SING. PAINE can’t SING. PAINE wants to SING. PAINE can’t SING.’
I think one thing that would help the story would be to use paragraphing. This is hard to read as it's basically all lumped together into one wall of text. You'd want to separate into paragraphs and with forums have a line of spacing between each one too so it's easier on the eyes. It's especially harder when the 'PAINE wants to ___ PAINE can't ___' lines repeating so often it's easy to lose the line.
I didn't feel too scared by this creepypasta; it seemed to lose a bit due to the over repetition. Jigglypuff-esque source of it is certainly a different direction to various others, but the execution could have been better.
To clarify, I don't mean just the 'PAINE can't ___' lines were overused:
My stupid friend-he always hacks his games. I sighed and ignored the text. When I tried to offer up the Jigglypuff for trade, text appeared ‘PAINE can’t leave you unless you SING.’ My god; my stupid friend! I sighed in exasperation once more and pressed A
Here for instance you state twice in two lines that the friend is stupid and that 'I sighed'. Earlier on you also mentioned the friend maybe having hacked the game too. Watch out for saying things over and over, and try to focus more on showing us on how the character feels and reacts. It's that that can help make a creepypasta story seem scarier.