The word "Only" was added later. Besides, that could easily be misunderstood.
"I did it in only 500 frames, how about you?"
Y'see? I'd personally recommend that you state "Must be in 500 frames or less",
because that can't be misunderstood.
Edit: This is what your post actually says:
Originally Posted by Kirby
i got 12 o.o in 500frames.
Edit:15 or 16 im not sure.
Looks more like you said that you got 12 in 500 frames. Keep in mind, i don't want
to offend you in any way, i just want to make sure that no more misunderstandings happen.