Never understood why they made it so that enemy's levels scale so tightly with that of playable characters. So first of all that.

There's the junction/limitbreak/battle system which is extremely flawed too, in an amount of ways that I can't possibly be arsed to type.

Would also like to see more focus on the SquallxSeifer love story. All we got in the original game was the odd hint dropped about Seifer's "romantic dream", relentless flirting and a kinky torture fetish scene. A small helping of side quests that offer a little more insight as reward for completion would be a nice touch.

In summary: Rehash the story, rehash the battle system. Maybe rehash some of the characters, maybe most of the characters. Remake FFVII instead.