dtgreene: Final Fantasy 7 (alternate version):
Make the game a 2D sidescroller.
Remove all RPG elements.
Player can now jump, and combat occurs on the main screen and is collision based.
Only one materia can be carried, which allows the use of a magic attack. Each materia can be used a certain number of times. (Think the sub-weapons in Haggleman 3, if you've played that.)
Potions and similar items can't be carried. Picking up a potion will heal you immediately.
Pheonix Downs give you extra lives.
At the start of each stage, and after each life, you can pick a character; each has different fighting styles.
2 player co-op added. (Makes more sense for a 2D sidescroller than an RPG)
Game is now linear without backtracking, with overworld segments replaced by outdoor stages. (Note, for example, a stage where you have to flee, on chocobo, from the Midgar Zolom.)
I can't believe you didn't mention wanting to see Shinra install gender neutral bathrooms at their corporate headquarters.