i did with my brother once when he had time and didnt mind, he doesn't play ff much though, and that was fun cause i'd just reached Dali, i was about 10 and it was the first ff i'd played, and he'd already got to near the end so it was great for me having support cause we worked as a team and have a similar battle style (pummel them with attack constantly and heal only when necesary, not as frequently as we should to keep safe) but when i tried with my friend in Mount Gulug it was terrible cause she was near the beginning and had to use every ability that she didn't have (most of them) and they didn't help at all and it was a huge pain she has an incredibly defensive battle technique that is so defensive it doesn't actually work, she spends far more time healing than attacking and then she dies despite the healing cause her characters MP gets exhausted and then she wonders why at it annoying so that didn't work out at all. i prefer fighting alone but i wouldn't say 'no' if my brother wanted to fight with me