1. KH1
The original Kingdom Hearts is legendary. It's the one. It's a marvel of gaming, a genuinely magical adventure with the perfect opening and final acts to bookend the whole experience. Every aspect of the game is filled with love and novelty. I can always come back to it and discover something new. It picked up the reigns where Ocarina of Time left off, and delivered a similarly satisfying journey that just stays with you. The music is sublime and transcendent. There is a profundity to the design work that is uniquely Kingdom Hearts, that goes to a place Walt Disney and Squaresoft hadn't yet reached, and haven't since. Dive to the Heart, Hollow Bastion, End of the World... These places are eerily pungent with spirit. It's a truly heartful game, and it still beats.
2. KH2: a classic action game in its own right. It didn't have to reinvent the battle system form KH1, but it did. The streamlined gameplay is a sleek and wondrous contraption, clinking kinetically within itself. It's fabulous. The whole production feels very deluxe. It's one of the most beautiful PS2 games, and the use of fisheye perspective is applied just right. The story is lopsided and inconsistent with the epic drama of the original, but nowadays I feel its obtusity is justified. It's a spectacular spiral into nothingness, unafraid to cast off any notions of what a Kingdom Hearts sequel should be and did its own thing.
3. DDD: Charming and oddly quaint, almost like it's consciously holding back. But it's fun to bounce around, and I appreciated the focus on characterization, relatively speaking. Yensid's arbitrary Mark of Mastery is a woefully uncompelling place to start a story, but I can appreciate a good dream. Traverse Town, The World That Never Was, Pinocchio were all welcome returns. This is the only game in the series that applies nostalgia (for itself) properly. It's an awkward game, but there's something affectionate about it that the other spinoffs don't have. It's unified by the carnival theme, and feels like more of a celebration of Kingdom Hearts than anything.
4. CoM (GBA): Beautiful sprite art, and a surprisingly grim story that redefined the tone and lore of KH, though of course KH2 redefined it again, leaving Chain of Memories as an odd curiosity peppered with interesting concepts and characters, most of which never found a way to be organically reintegrated. It's a treat, but more bitter than sweet.
5. BBS: This was the last title in the series with a real spark of ambition behind it. There was that initial vision of grandeur, armored keyblade warriors fatefully gathering on an ancient battlefield. But it never quite came together and reached that space opera climactic grandiosity. The script is an exhausted scramble, desperately trying to jam the pieces together. It wears very thin across three playthroughs. The new mechanics and concepts are all half-baked, but it's still an enjoyable enough game to play through because it does have the style and skeleton of KH.
6. Days: It's a good story. It feels personal, and wistful. The gear system was cool. Unfortunately, the gameplay is simply functional and the worlds are lacking creativity when they aren't 1:1 copies of maps from KH1 & 2. I'm tempted to place this above BBS, because the feeling of loneliness within an institution and complications between friends is handled so much better here. But I can't ignore how perfunctory most of the missions are.
7. KH3: The Wound itself. The game that lost its heart. I had made excuses to myself for the handheld spinoffs, but this was proof that something had gone deeply wrong within the franchise years ago. The taste level has plummeted. The elegance, gone. Corona and The Final World were indeed lovely, but that's simply not enough for me to forgive this catastrophe. There are probably several reasons why KH lost its luster in the corporate crunch, and all must be addressed if this series is ever to rise from the ashes and become the glorious extravaganza it still can be. KH should be held to a higher standard because it has that potential, to go to infinity and beyond. Maybe, someday.
8. Re:coded: It's cute. Some cool mechanics, but the bughunting is just too repetitive and the stakes could not be lower. I'm sure the original was an impressive phone game, but ultimately it's a trifle.
9. Re:CoM: How did this even make it through the planning stage? Instead of elevating Chain of Memories in any way, or adapting it to best fit a 3D medium, it aims for the bare minimum, and in doing so disgraces the original and the franchise overall. It's not fun.
10. x/unchained x/union cross: There's no excusing this. Yes, the story does possess a measure of intrigue that recent other KH games lack, but it's a cheap mystery told at a snail's pace within a dreadful app that preys upon addictive personalities with credit cards. It's a shame that this story, and now Xehanort's, have been relegated to this garish thing.
I don't feel 0.2 stands well enough on its own to judge as a full game, but I'd probably place it alongside BBS. I don't need to factor in Final Mixes or Re:Mind because they didn't change my estimation at all, only reinforced how I already felt about the games on release.