Haven't played one KH game and I'm not planning to do so in the future. The dozens of games on many different consoles and their stupid names really put me off.
KHIII looks very pretty though...but it's probably the next FFXV isn't it? Nomura will delay it at least a couple more years.
You can simply play I, II and the one on PSP. The rest you can read online, I think. KH has such a shitty plot after the first because it tries to be deeper than the heartfelt Disney + Anime style story it is.
Then it just becomes Nomura wank.
Just enjoy the scenery and the music. I also find the gameplay from II onward terrible but that's just me (it's mindless button mashing without puzzles and exploration like the first).
That said, I hope KH III comes sooner than expected and does well. It's FFVII I secretly wish to bomb. I am a heartless monster, I know, but Nomura already did enough damage to the world of FFVII. He does not really get it and wants it to be darker and broodier than what it is. The ecological message is always thrown outta the window with him and Cloud becomes a fucking unemotional depressed slate when in the original he laughed, he cried and sulked a lot, he got fucking pissed, et cetera. (I almost typoed et cetra lolololololololol)
I swear that remake
1) Better be at least unoffensive not good not bad. If it's good (I doubt it), then yay.
2) Will come out in at least 3 years.
3) We will probably see KHIII first.
4) WILL ADD COMPILATION SHIT IN IT! D: