I assume you are planning on playing Re:Chain of memories, the remastered version and NOT the original GBA one? There are slight differences between the two, so just checking.
1- Is the gameplay similar to a regular RPG or is it the same gameplay as the rest of the series ?
Not sure what you mean by "regular" RPG, but basically the answer to your question is NO. CoM is the biggest odd one out in terms of game play changes. For starters, the entire battle system is structured around cards. You collect different types of cards, either attack cards (with a keyblade on them), magic cards (of all types of spells like fire, blizzard, cure, aero, stop, etc), enemy cards (cards depicting heartless or other bosses that have "special" affects when you use them in battle) and item cards (that refresh your deck). ANY move you want to do in battle requires you to play a card to do it (the exceptions are dodge roll, which you can do freely and jumping). All Heartless and bosses you face will also have their own decks that they play from.
Furthermore, each card (apart from enemy cards) will have a value system between 0 - 9. Any higher number will "trump" a lower number. So, if you are fighting a heartless and it plays an attack card with a value of 6, and at the same time you play an attack card with a value of 5, the heartless is going to hit you unless you dodge. Also, it is a BIT confusing, but 0 is actually both the weakest and the strongest number. So if you play it after a heartless has played its card of 6, the 0 will win. But if you throw down a 0 and a heartless THEN plays a 6, you lose.
There are other intricacies that I won't go into, but the big one is that "abilities" are actually card combinations. You can do something called "stocking" where you save cards to play at once (to increase the total of your card values) or to try and activate an ability. These have different requirements that you have to have a bit of pre-planning to do. So a lot of the game is arranging your deck within the constraints of your CP (maximum value number of cards you can hold in your deck).
When you level up, you can choose to increase your HP (makes it harder for you to die), your CP (lets you have a bigger deck) or possibly learn an ability (like strike raid, slide dash, etc). (again, those abilities are only useable via card combinations).
In that sense it is definitely an RPG, but there is a bit of a strange freedom (in that you choose what you get when you level up) but at the same time a huge sense of constraint (because all your actions are tied to cards).
You also have to be careful not to run out of your entire deck during fights too. Because then you...kinda can't do anything. You can "reload" cards that you have already played, but not all of them come back, and reloading also takes time where you have to stand around and hold a button down so you are a bit of a sitting duck, too.
Luckily, you also can get Friend cards that drop randomly that you can play where various allies help you out for a move. It helps, but it's best not to rely on it.
It's a really interesting system, and there is a TON more to it. A lot of people get reaaaally put off when they first hear that it's so completely different game play wise, but it's got a ton of versatility if you know where to look. Honestly, though, I think the original CoM is best because you can't cheese the attacks as much (by just dodging rather than having to use a 0 to break them), but having the fully voiced cut scenes is nice.
So yeah, go into it expecting it to be pretty different. But keep an open mind and see if you like it.
Also keep in mind it WAS originally a game for the GBA, so it is pretty limited in what it does. It's nothing like a full ps2 game. That being said, at the time when it first released, it was pretty impressive having a few full cut scenes with almost ps2 quality graphics. The sprites were really cute and it had some interesting quirks to it. The ps2 version they made more user-friendly and forgiving, but I always at least try to recommend if people enjoy the card system to at least get an emulator or something and check out the original game.
2- This question is for chain of memory and birth by sleep, how long will it take me to finish the game ?
This is hard to say because I don't know how much of a completionist you are. If you are talking just straight, set on normal mode just doing story, then you are looking at probably 20 - 25 hours for Re:CoM and maybe 30 hours ish for BBS. I tend to take a way longer time with CoM because I have a compulsive need to unlock every room, including the special golden treasure rooms which takes a bit of farming sometimes. Also, trying to be as spoiler free as possible, once you beat CoM the first time, there is an additional "mode" that unlocks a secondary story. It's shorter, but also pretty important to play through. BBS is also broken up into not only 3 separate character play throughs, but it has some extra stuff tacked on once you beat the story with those 3 characters. The three of them play pretty differently, so I tend to find I spend a lot more time on the character I enjoy playing as more than the other ones so it's a bit uneven.
Hope you enjoy!
