>>718294084
>K1
They added several new cutscenes at the start of each chapter for most of the game that flesh out Nishiki. In the original Nishiki was a literal who, he showed up in around five or six total cutscenes in the entire game, only spoke in three of them, and was a complete joke of a character. He did not matter.
Kiryu only had one style which was the Dragon of Dojima. Rush, Beast, and Brawler are all retconned into the mix and he shouldn't even be using them if he has DoD because DoD is just all of them combined into one super style that's just better than all of them standalone.
All of Majima Everywhere didn't exist in the original and none of the abilities were tied to it. The only places you got abilities from were the coin lockers or Komaki. Komaki himself is also locked behind Majima Everywhere in K1 which sucks if you did too much of it since he's locked for multiple chapters. In general the experience in K1 is made much worse because of how much Majima locks you out of in everything and DoD is basically unusable unless you're a 100%er in K1.
The funeral battle with Majima didn't exist in the original which is an improvement from K1 because it really should have.
The pier thing with Majima only exists for Majima Everywhere and makes no sense with the main story while also ruining what the main story was trying to do.
In general Majima Everywhere flanderizes Majima and makes him appear way too often which guts his story appearances.
The atmosphere is different due to the fixed camera angles.
The music is worse on the whole in K1. Most of the changes are just awful.
Several substories were added to K1, most notably the interview and the fan dancing one.
The coliseum was completely different in 1 and also required you to unequip everything unlike K1. K1's is the more modern coliseum structure introduced around 4ish.
Most of the movesets in K1 are taken from Kenzan, 3, 5, and 0, not 1, and several movesets were gutted like Komaki and Amon.

K2 next.