tldr; This game is very much worthwhile, though some things have changed.

At Length:
Let's talk about what has changed from a mainline title.

Item level on ingredients outside of cooking is no longer a thing, so the arcane crafting system is not a thing in this. No copying boss techniques with that.
However, you can still tame boss monsters, so it barely matters. What it gets replaced with are relics that serve as a multi-tool between swapping magic, farming tool functions, etc on the fly.

Farming is easier in this game than it ever has been, you can enter a top down grid and water crops, or just assign villagers to handle all farming related tasks for you (They'll handle it about as well as monsters do in previous titles, though they also harvest and store stuff for you and plant at random based on your own inventory)
Again, sacred relics are sort of a hybrid as well of farming tools and magic wrapped in one.

Here's a big one. Rune Points. Rune Points are no longer the blood, sweat and tears stamina that goes down when you do literally anything (Chop wood, swing a sword, craft something, etc).
Instead, it's basically just MP and only MP, being consumed only when you use a sacred relic's magic.

To compensate for this, crafting is instead barred by money. You need to use a blacksmith's shop to forge and you need to pay your blacksmith in both materials and gold. No more slaving away in your overtuned nuclear science lab drinking 25 grape liquors and forging a waterpot that can kill god.

Last change off the top of my head: Recipe Bread. Not a thing anymore.
Instead, you search for altars and frog statues and pay your respects. There is no limit per day, rather the recipes themselves are tied to exploration and finding things in the world. Which, with the ability to jump and a lot more freedom of movement given right out of the gate, is a lot easier than you might think.
Frogs and shrines will also be marked on your minimap with which ones you haven't found yet, so the game helps you more than it hinders you in this regard. You may need to solve puzzles to find stuff though.


Closing thoughts:
I'm impressed. Rune Factory 5 pigeonholed itself into living in 4's shadow and being ultimately a pale reflection. Satisfying with its QoL but tragically burdened by a very empty and flat overworld and some clunky writing delivery and presentation. (In spite of these things, it was still alright! Feel free to read my review on that if you're doubting me.)
Instead, with Guardians of Azuma they decided to experiment and go outside the box again. Sort of the way they would with Tides of Destiny (Air Fishing...?) or Frontier (I miss my mail delivery NPC....)
As a non-numbered title, these particular spin-offs exist as an experiment. Kinda like Pokémon Legends Arceus vs... all the recycled titles....
I'm relieved they chose this path rather than "playing it safe" with every title going forward. Things have changed and though I miss my atomic watering can... Rune Factory 4 and 5 still exist and were the only games that had that to begin with. Moreover... I can still *play* those games.
By stabilizing gear progression and instead giving you invincible bullet time dodges, being able aim your bow on the fly and other crazy nonsense, the game does a really good job of handling 3D action combat and involves less fumbling around your backpack.

All in all, this game is very good! Go play it, talk about what you liked and talk about what you'd want going forward. (For me, I still want Hell Mode. Hard Mode is surprisingly balanced, but I want to suffer since Rune Points can't kill me anymore.)

Extras:
Villagers. The Villagers have their own unique kits again and it makes me so happy. They don't have an LB like they did in 5, they don't transform or anything crazy like they did in 3, but much like 4, they have very cool attack patterns that fit in with what you see in their story and aren't just "Broadsword user 7". This makes me happy.

tldr; This game is very much worthwhile, though some things have changed. At Length: Let's talk about what has changed from a mainline title. Item level on ingredients outside of cooking is no longer a thing, so the arcane crafting system is not a thing in this. No copying boss techniques with that. However, you can still tame boss monsters, so it barely matters. What it gets replaced with are relics that serve as a multi-tool between swapping magic, farming tool functions, etc on the fly. Farming is easier in this game than it ever has been, you can enter a top down grid and water crops, or just assign villagers to handle all farming related tasks for you (They'll handle it about as well as monsters do in previous titles, though they also harvest and store stuff for you and plant at random based on your own inventory) Again, sacred relics are sort of a hybrid as well of farming tools and magic wrapped in one. Here's a big one. Rune Points. Rune Points are no longer the blood, sweat and tears stamina that goes down when you do literally anything (Chop wood, swing a sword, craft something, etc). Instead, it's basically just MP and only MP, being consumed only when you use a sacred relic's magic. To compensate for this, crafting is instead barred by money. You need to use a blacksmith's shop to forge and you need to pay your blacksmith in both materials and gold. No more slaving away in your overtuned nuclear science lab drinking 25 grape liquors and forging a waterpot that can kill god. Last change off the top of my head: Recipe Bread. Not a thing anymore. Instead, you search for altars and frog statues and pay your respects. There is no limit per day, rather the recipes themselves are tied to exploration and finding things in the world. Which, with the ability to jump and a lot more freedom of movement given right out of the gate, is a lot easier than you might think. Frogs and shrines will also be marked on your minimap with which ones you haven't found yet, so the game helps you more than it hinders you in this regard. You may need to solve puzzles to find stuff though. Closing thoughts: I'm impressed. Rune Factory 5 pigeonholed itself into living in 4's shadow and being ultimately a pale reflection. Satisfying with its QoL but tragically burdened by a very empty and flat overworld and some clunky writing delivery and presentation. (In spite of these things, it was still alright! Feel free to read my review on that if you're doubting me.) Instead, with Guardians of Azuma they decided to experiment and go outside the box again. Sort of the way they would with Tides of Destiny (Air Fishing...?) or Frontier (I miss my mail delivery NPC....) As a non-numbered title, these particular spin-offs exist as an experiment. Kinda like Pokémon Legends Arceus vs... all the recycled titles.... I'm relieved they chose this path rather than "playing it safe" with every title going forward. Things have changed and though I miss my atomic watering can... Rune Factory 4 and 5 still exist and were the only games that had that to begin with. Moreover... I can still *play* those games. By stabilizing gear progression and instead giving you invincible bullet time dodges, being able aim your bow on the fly and other crazy nonsense, the game does a really good job of handling 3D action combat and involves less fumbling around your backpack. All in all, this game is very good! Go play it, talk about what you liked and talk about what you'd want going forward. (For me, I still want Hell Mode. Hard Mode is surprisingly balanced, but I want to suffer since Rune Points can't kill me anymore.) Extras: Villagers. The Villagers have their own unique kits again and it makes me so happy. They don't have an LB like they did in 5, they don't transform or anything crazy like they did in 3, but much like 4, they have very cool attack patterns that fit in with what you see in their story and aren't just "Broadsword user 7". This makes me happy.