Game really deserves a Remaster to address some of the basic shortcomings it has, like the camera being too zoomed in/moving erratically, an updated HD UI, change party leader during battle, no game over when party leader dies, etc etc. Maybe rebalance the progression system for better flexibility at the beginning, increase enemy aggression and turn speed. Add a side hunt in each area from earlier on in the game that you'd turn in at the save points. Redesign the world map to include Cocoon/Pulse in a 3D hologram model.

I've thought about 100 different little ideas for a FFXIII Remaster in the last year.