After taking a week and change off since beating the game with 100% shrines here are some improvements that I'd want for the next game.
Before I start, this game still gets a 10/10 in my books.
More variety on melee weapon archetypes. I don't mind that there are Swords, Great Sword, Spears and Boomerangs, but the move set didn't change for a single one of those archetypes with regards to weapons in those class. For example, the Chainsaw that I bought from Robbie and co acts just like every other great sword archetype. I wish it had at least some uniqueness to it considering it was vastly different looking from other weapons...and it was a chainsaw.
The Souls series for example(Demon,Dark, BloodBorne) will give you weapons that might have the exact same attacks set as other weapons but there will be one unique attack about them(boss weapons generally). So maybe they could have had something that once you're done your spin charge with chainsaw link does a chainsaw animation for more damage. I think it would add to the diversity and excitement of getting weapons.
I miss the anticipation of opening up a rare-chest. Could it be a heart piece? Could it be a new weapon to beat a dungeon? Now I'm not saying bring back that dungeon item chest because I love how you can solve everything from the very beginning, what I mean is that I hit a point early on when the chests no longer got me excited. I'd know it was a weapon I'd already seen, rupees, ancient cores, arrows etc. Only time I got really excited was when I got a piece of armour, needed more things like that IMO.
Let you take your sheikah slate to another level even. Let it have even more upgradeable parts, let you upgrade the magnet allowing you to carry even larger objects etc. Feel like they just gave it to you with the essentials and they had minimal upgrades(not all were).
Let you call your horse ANYWHERE on the map. I don't think a single person would have a complaint about this, but that's just me.
Shock Arrows effect water, fire/bomb arrows effect grass and explosive crates, why can't ice arrows effect the environment? Unless someone knows how they do, because I never got it to work, even in water lol.
That's all I have for now.