If you were going to build a Studio Ghibli/Zelda-flavored campaign, what elements would you include?

[TerraDave]

For Ghibli: flight. There are a few exceptions for the particular movies, but being able to fly through some means is very important to be ghibliesque.

 

[CreamCloud0]

i think building highly themed areas (this is the water area, this is the caves/mountain area, this is the machine/factory area) with a town or village of an apropriate species and their accompanying 'dungeon' which is the source of their troubles in some form or another, putting a 'key magic item' in the dungeon is probably going to go a long way to 'zelda-fy' the theme.

this is the mystic forest where the nature spirits live and are troubled by a seeping poison, you use a staff of bloom and decay to grow and shrivel various plants to get around
this is the grand bathhouse in the spirit world which is ruled by the evil witch, you use the lantern of revealing here to dispel illusions and reveal invisible stuff
this is the ruins of the cloud palace tower filled by the ancient golems being attacked by the giant thunderbird, you use a wand of reverse gravity to functionally flip gravity and solve rooms upside down

 

[Whizbang Dustyboots]

i think building highly themed areas (this is the water area, this is the caves/mountain area, this is the machine/factory area) with a town or village of an apropriate species and their accompanying 'dungeon' which is the source of their troubles in some form or another, putting a 'key magic item' in the dungeon is probably going to go a long way to 'zelda-fy' the theme.

this is the mystic forest where the nature spirits live and are troubled by a seeping poison, you use a staff of bloom and decay to grow and shrivel various plants to get around
this is the grand bathhouse in the spirit world which is ruled by the evil witch, you use the lantern of revealing here to dispel illusions and reveal invisible stuff
this is the ruins of the cloud palace tower filled by the ancient golems being attacked by the giant thunderbird, you use a wand of reverse gravity to functionally flip gravity and solve rooms upside down

I would play in this world.

 

[TwoSix]

Break! RPG (which had a Kickstarter I backed) is the closest thing to a Studio Ghibli/Zelda hybrid I know; they're definitely two of the most obvious formative influences.

 

[CreamCloud0]

tangentially to my previous comment of making highly themed areas, by telegraphing the types of dangers and obstacles the players will be facing it allows you to go ham on the difficulty but given the players properly prepare themselves with available spells on their lists or items at the stores they'll be optimised for those challenges and it should balance out with the players being satisfied because their preparations paid off and it made that super hard fight way more managable for them.

going into the venom swamp? well the shopkeep is selling a ring of poison resistance and a wand of cure disease
the iceberg cavern village has insulated clothes, an icebreaker hammer and someone willing to teach your sorcerer burning hands.

 

[BookTenTiger]

tangentially to my previous comment of making highly themed areas by telegraphing the types of dangers and obstacles the players will be facing it allows you to go ham on the difficulty but given the players properly prepare themselves with available spells on their lists or items at the stores they'll be optimised for those challenges and it should balance out with the players being satisfied because their preparations paid off and it made that super hard fight way more managable for them.

going into the venom swamp? well the shopkeep is selling a ring of poison resistance and a wand of cure disease
the iceberg cavern village has insulated clothes, an icebreaker hammer and someone willing to teach your sorcerer burning hands.

Thinking especially of Zelda, local communities often don't find the habitats too threatening. For example, you have lava-loving rock people living around the volcano, or fish folk living around the water temple.

However, outside forces then make the environment more dangerous. An angry dragon is making the volcano erupt. A sorcerer is turning the ocean to ice.

The local folk might have resources to help the characters with environmental hazards, but they still need the characters to help with whatever threat is disrupting the natural order of things.

In fact, a big theme of both Zelda and Miyazaki is the corruption of nature. Nature can be dangerous, but it's far more dangerous when humans (or other entities) interfere with it.

So I think having themed areas and themed communities is good, but it would also be good to go a step further and think about what forces are corrupting the natural areas.