I'm just gonna go over the entire series, excluding Link's Awakening, and the Oracles games, because I haven't played them. Also, gonna exclude the first game in the series because this post is about how sequels have improved or remained stagnant.
Link's Adventure: Not really a Zelda game IMO. It abandoned most of what made the original so good.
A Link to the Past: This Zelda was more linear than the original, but that was a good thing. No longer could you wander around not knowing where to go. I'm all for open worlds, but there's something to be said about keeping the player in a certain area while he figures things out. Even BotW did this with the great plateau. Part of the reason why BotW's dungeons aren't all that good is because the designers had to make four dungeons without knowing what tools the player already has. When the player is given objects in a set order it becomes a lot easier to design around what you know the player will have at each point in the game. Even though ALttP is linear, it still gives the illusion of freedom, without leaving the player lost. This Zelda also introduced having the player switch between worlds. Ocarina of time would change this to time traveling, but the end effect is the same.
Ocarina of Time: What can I say? It took Zelda into the 3D area, and paved the way for a lot of titles to come after it. Analog movement, lock on camera, playing songs, and NPC voice bytes were all introduced in this game. NPC voice bytes are when you talk to a character and they make a sound that gives you a vague idea of what their voice might sound like in your head.
Majora's Mask: A short Zelda with only four dungeons, but a crapton of intricate time traveling and mask collecting aspects. Majora's Mask also told us that Zelda games didn't always have to occur in a medieval style Hyrule. This paved the way for games like Windwaker, Skyward Sword, and BotW. Putting Masks on to transform into characters and change abilities didn't return (I wish it would!), but it was a sort of precursor to what Nintendo is doing with Odyssey.
Windwaker: The art style of this game is iconic, and it contains a decent amount of exploration, but IMO this is where Zelda really started to go downhill and get samey. Gameplaywise this didn't really add anything new to the series. There weren't that many dungeons, and it lacked the intricacy of MM. Having played the remaster, makes me realize just how much of a chore sailing was. Wait, I take it back. Windwaker did add something new to the Zelda series. It added padding. The worst parts of Skyward Sword, and Twilight princess got their start in the Triforce fetch quest. Don't get me wrong I like Windwaker, but it was where Zelda started to get a little stale.
Twilight Princess: This didn't add anything new to the series other than waggle controls, and motion based aiming. At least this game had eight dungeons. I liked this Zelda but it was kind of samey.
Skyward Sword: This is the reason why BotW exists. You see Skyward Sword was linear. Too linear. Fans that didn't like the game loudly told Nintendo to make the next Zelda more of an openworld, and they obliged in spades. Skyward Sword only had a single town, barely any overworld (a few islands in the sky), and it was riddled with padding. At the very least this game had pretty good dungeons. Motion controls worked fairly well and added something new. But to be honest I didn't like the sections of BotW where I had to use gyro controls to solve a shrine.
BotW: FINALLY! This is the first Zelda since Majora's Mask that really innovated. It's also the first Zelda since Ocarina of Time that both heavily innovated, and was of decent length. There's just too many things to list that got added with this one. Climbing, Physics, Breakable Weapons, Elemental Effects, a massive, massive, MAAAASSIVE world, stealth, any melee weapon that is not a one handed sword etc. Nintendo took a look at what other open world games had been doing at the time and was like: HOLD MY BEER!
BotW II: And here's where I wish Zelda would go from here. Nintendo spent a bunch of time making new assets for BotW. Why not pump out a sequel with 8 dungeons that are more fun and intricate than the four we got in BotW?Just use all the assets from BotW ala Majora's Mask. Put it out in 2019. Restrict what kind of weapons can be used in dungeons, and bring back a little teeny tiny bit of linearity that I talked about in ALttP, while still allowing the player to use whatever they like in shrines and the open world.
