I played the PS4 version on the 1.5/2.5 collection.
I tried giving this game a genuine chance after dropping it the first time very early on and I nearly got to the end of Sora's story but after grinding for hours and still getting stuck on the final Riku Replica fight I just couldn't take it anymore man.
A lot of people say the combat can easily be broken with sleights but everytime I use them I typically get countered with a sudden 0 card, wasting my cards until I have to stand still and recharge which leaves me wide open. I try to heal but get countered with higher numbers or 0 several times, I can't set up moves because I have to try avoid getting hit AND pick each correct card to set up. There are moments where enemies will swarm you so you don't have time to set up because you have to keep dodging since there's no block button.

Never before has a game made me more frustrated with its awful combat like this one. The only things this game has going for it is pretty good villains and Lord of the Castle is a phenomenal track.

But yea, I've played 10 hours of this and I couldn't take it anymore. It's a shame too because this game would've worked if it was turned based.

Holy fuck, this game is shit. I literally had to force myself to keep going and finish it

Positives
1. If you can get the higher leveled sleights, they're fun to use
2. The soundtracks good but only by default since it uses a lot of KH1's Songs

Negatives
1. This game arguably started KH's story becoming confusing. It throws so many concepts at you that you NEED to keep track if you don't want to be hopelessly lost during KH2 (ex: castle oblivion, organization 13, Sora going into a deep sleep, twilight town, the whereabouts of Riku and Mickey, etc.). It''s even worse if you consider the gba version on release when people thought they could skip it since it was on a handheld only to come to a rude awakening
2. A significant amount of the graphics are recycled from KH1 which isn't a problem on it's own but the environments are so barren and boring compared to KH1 that it just feel more insulting
3. The randomly generated level design sucks. It recylces the same layouts a lot and is way too underpopulated and boring.
4. The story within the disney worlds are almost carbon copies of the one's from KH1 expect they kinda revolve around memories and the in engine cutscenes are animated stiltedly and lazily.
5. Sorting through your deck to find the best cards for the situation can be very frustrating considering that you have to not only level up but also choose to get more card points and sacrifice health or new sleights for that level up which on your first play through, you wouldn't know the optimal decision to make so you'll either not have a comfortable amount of health the survive the bosses, you'll not have many cards in your deck for any and all combat, or you'll have a lot of sleights with barely any of the cards to use them
6. The combat itself is fine but can be either very infuriating with constant card breaks and low level cards or completely broken in your favor with busted slights and card combinations. There is hardly ever an in between
7. The bosses are the definition of unforgiving. They expect you to either rock the very broken sleights or constantly spam elemental weakness. Difficulty in itself isn't the issue, the issue is that the bosses give you zero breathing room for any other strategy, it's either those two or die.
8. While the prospect of the Riku story is great and it's better than Sora's technically, It's still mostly the same as Sora's story with the same problems and it's crucial for the story so if you wanna follow that, you can't skip it (I honestly recommend watching the cutscenes online if you can't stand this game)

in short, fuck this game from the bottom of my heart