Wow,you must really adore Final Fantasy!
I don't really find problems in this one,other than the fact that Tifa's eye is a bit forward-er than it should be and her nose is pointier.
You used colors and shading very well,because the water colours are darker in some places that should be dark(example:Cloud's vest)
You also used that starry cosmo effect where you leave dots on there and they resemble stars!
The anime technique,the clothes,the hair,the characters are all captured perfectly and also it's cool that you painted the eyes a bit...non-yellow
Overall an almost perfect piece that reminds me of the times FF7 wasn't screwing with your emotions.I know that any FF fan of this will enjoy!Happy new year!