A) a combat system with a bit more depth. doesn't have to be hard or overly complex but something a bit more engaging. something that makes encounters a joy rather than a hurdle.
B) revisit the collectable items. some things are getting too classic. puzzles that are exactly the same as the previous 3 games aren't fun the 4th, 5th, 6th time through. i would be up for fewer items that were more useful though the entire game (not just one dungeon). just tweek thinks enough that i can't say something like "oh, looks like i'll have to come back once i find a hookshot to get that heart piece". if i can correctly call the item before i earn it the joy of discovery is lost.
C) zelda gives the illusion of open world without the ability to actually choose your own path. make the game actually non-linear (like MM but even moreso) so i can truly choose my own path (or at least feel like i did).
D) more engaging story.
zelda doesn't need a complete overhaul. it just needs to grow up a bit from OoT. that was an amazing game in it's day but things have evolved and the formula is getting dated relative to what everyone else is doing.
