Well, to get the full Kingdom Hearts story, you definitely can't miss the main numbered installments like Kingdom Hearts III. But don't forget about the compilations and side games, as they all contribute to the rich and complex narrative of the franchise.
I'd recommend playing the various spin-offs and remasters too. For example, Kingdom Hearts: Birth by Sleep and Kingdom Hearts Re:Chain of Memories help fill in important plot details. Also, the mobile game Kingdom Hearts Union 蠂 [Cross] adds some background to the lore.
I'd recommend starting with the original Kingdom Hearts and its sequels. They lay the foundation for the story and introduce key characters and plotlines.
The Legend of Zelda series is a great example. Games like Breath of the Wild have an immersive story where you, as Link, are on a quest to save Hyrule. The open - world exploration and the way the story unfolds as you discover more about the land and its history is somewhat similar to Kingdom Hearts.
One game like Kingdom Hearts story is Final Fantasy. It has a rich and complex narrative with elements of fantasy, magic, and a battle against dark forces. The characters are well - developed, and the world - building is extensive, much like in Kingdom Hearts.
The order is: Kingdom Hearts: Birth by Sleep, Kingdom Hearts, Kingdom Hearts: Chain of Memories, Kingdom Hearts II, Kingdom Hearts 3D: Dream Drop Distance, Kingdom Hearts III. But this can be a bit complex as there are also other titles like Kingdom Hearts: Re:coded that fit into the overall story timeline in different ways.
The order is Kingdom Hearts: Birth by Sleep, Kingdom Hearts, Kingdom Hearts: Chain of Memories, Kingdom Hearts II, Kingdom Hearts 358/2 Days, Kingdom Hearts: Coded, Kingdom Hearts: Dream Drop Distance, Kingdom Hearts III, and Kingdom Hearts: Melody of Memory.
It goes Kingdom Hearts: Birth by Sleep, Kingdom Hearts, Kingdom Hearts: Chain of Memories, Kingdom Hearts II, Kingdom Hearts 358/2 Days, Kingdom Hearts: Coded, Kingdom Hearts: Dream Drop Distance, Kingdom Hearts III, Kingdom Hearts: Melody of Memory.
Well, 'Kingdom Hearts 1' is the foundation. Without it, you won't understand the whole concept of the Heartless, Keyblades, etc. Then 'Kingdom Hearts: Chain of Memories' which is important for the transition of the story. 'Kingdom Hearts 2' continues the main narrative. Also, 'Kingdom Hearts: Birth by Sleep' is quite significant as it reveals a lot about the past of the characters and how the whole situation in the Kingdom Hearts universe began.
Kingdom Hearts: Birth by Sleep, Kingdom Hearts, Kingdom Hearts: Chain of Memories, Kingdom Hearts II, Kingdom Hearts 358/2 Days (although its story is intertwined with the others), Kingdom Hearts Re:coded, Kingdom Hearts: Dream Drop Distance, Kingdom Hearts 0.2: Birth by Sleep -A Fragmentary Passage-, Kingdom Hearts III.
Well, sometimes you can find it on subscription-based services such as Netflix or Amazon Prime Video. But availability might vary by region. Also, check the official Kingdom Hearts website for any specific streaming partners they recommend.
By expanding on the story, the Kingdom Hearts 3 Official Novel makes the overall experience more immersive. It can flesh out the relationships between characters. For example, we might get more insights into how Sora, Donald, and Goofy's friendship has evolved over time. Additionally, the descriptions of the battles and magic in the novel can be very vivid, almost making you feel like you're right there in the middle of the action, even though it's a different medium than the game.