I'm playing them all in preparation for KH3 and this is my first time with the series. I beat 1 and honestly thought it was pretty good, it hasn't aged well (I mean it feels it's age) but little has from back then. I'm on the last level of Chain of Memories (3D one via 1.5 -2.5) and my God, this one however I fucking hate. Repetitive, slow, stupidly hard... I like the plot, the whole memory thing is a cool concept but damn, I can't stand this lazy, asset reusing excuse for a game.
Can anyone tell me if it's actually needed to play as Riku in Chain of Memory after i beat it with Sora? Is it just a bonus or is there actually a plot to it worth knowing?
I'm in the same boat as you right now. I bought the "Story So Far" collection because it was dirt cheap, and to make matters worse, I'm a trophy hunter and Re:Com has some downright sadistic requirements (Like getting to both Sora and Riku to Lvl 99...still working on it)
To answer your question, Yes, Riku is sadly manditory since it deals with unique organization members that weren't even shown in the Sora storyline and it kickstarts his own character progression and introduces another important character.
I have learned to get used to the card based gameplay because in Re:com, it can be easily cheesed, even in Proud Mode. Blizzaga and Firaga in particular are just stupid powerful, and Riku's dueling + his Dark Mode makes his easy too so long as you level accordingly.
So the last boss in Chain of Memories is impossible. Seriously, fuck this game, I'll just watch the end on TY and move on. Please tell me this card bullshit never returns throughout the series....
The last boss can be cheesed using Firaga. No kidding, even in Proud mode. Just stock up on Fire Sleights and use Jafar and Marluxia enemy cards. Otherwise, you can also use Lethal Frame.
His difficulty depends on whether or not he whips out Doom during the brief moments when he is not stun-locked. Ragnarok can also be used for the first phase, since it is powerful and you can even use the Kingdom Key low cards for it.