For one, I'd make Jenova a much more visible, more human-looking character. Yes, she's the central baddie in the game, but you never actually see her, except in the tube in the Nibelheim Reactor flashback. You have to fight her, but those are only pieces of her. Make her a human-looking, obviously ebil force who appears to torment you throughout the game (as more than just an occasional boss; really screw with your mind, ya know), and I'd love it. Actually, Jenova would have a ton of fans, if they only developed her character a bit more.

Two: Get rid of the WEAPONs. Not because I don't want to fight them; actually, it's my favorite part of the game. But allowing you to fight them, and allowing you to win in those fights, certainly makes the planet look bad. They're meant to wipe out everything, and (at least, I've always believed this) kill enough things so that the Planet has enough spirit energy to heal the wound it knows is going to be created by Meteor. And yet, you defeat them, possibly quite easily. You'd think they'd be so powerful that no human could kill them.

And that's just about it. I actually like the little Lego people, as I call them. And the graphics for the locations aren't shabby. I do wish there was something in the game, like a mini-soundtrack, so you could listen to all the songs whenever you wish. I've had a couple games like that, and I did enjoy it. Other than that, it's one of the best games I've ever played, as far as the storyline goes.