Average of all the games.

Kingdom Hearts Final Mix = 9/10
Kingdom Hearts Re: Chain of Memories = 7/10
Kingdom Hearts 358/2 days = 6/10
Kingdom Hearts 2 Final Mix = 10/10
Kingdom Hearts Birth by Sleep Final Mix = 9/10
Kingdom Hearts Re: Coded = 4/10
Kingdom Hearts Dream Drop Distance = 8/10
Kingdom Hearts 0.2 = 7/10
Kingdom Hearts X Back Cover = 7/10
Kingdom Hearts 3 = 10/10

Total = 77/10 which I will round up to 8/10. Bundle's very worth it.

Seeing the same cast of characters follow one continuous plot over 20 years of publication is common for comics and books, but it almost never happens in video games. Games series tend to either have a new cast and plot each game, like Final Fantasy, or have the same cast but no continuous plot, like Mario. The only series I can think of that comes close to a continuous cast and plot are Ys, which keeps the same protagonist and best friend but has almost no other returning characters; Trails, which keeps the same setting but the protagonist and party members change often; and Metal Gear, which has ended.

Kingdom Hearts is an outlier in this regard. If you want a story focused video game series with the same cast and plot that spans twenty years, then Kingdom Hearts is your best and probably only choice. Now I don't actually like to read those books and comics that span twenty years because I find them repetitive, but Kingdom Hearts doesn't have this problem because the gameplay changes significantly from game to game. The first is focused on platforming with hack and slash, then it's a card game, then it's a character action, then a few games here are just movies, there's one with monster collecting, etc. It's varied and unique.

Another draw to this series is the Disney characters and worlds. Again, I don't actually care much for Disney movies, but I love them here because of the variety. One world might be in a whale, another in a computer, one is underwater, in one you sail a boat, etc. While there's a core cast that is recurring there's tons of Disney characters to add variety to the story and the aesthetic.

Is Kingdom Hearts always good? No. There are a lot of things I dislike. Some games I don't like the combat, some characters I don't care for, some worlds overstay their welcome, etc. but this is really about being more than the sum of its parts. If I had to rate each game in the series and average them out, I'd probably end up with a 7.5/10, but as a whole package, being an incredibly unique media experience that you won't find anywhere else, it has to be a 10/10.

This is one of those games that really just strike a bond with you. The writing is very very very not interesting at all. Most of the games content feel like filler. But Kingdom hearts games do have very unique combat mechanics and gameplay, although they change it out almost every game. The only notable characters are the main cast and the original convoluted story it comes with.

All in all, most people stuck around for the nostalgia but theres actually alot of fun and memorable experiences to be had, although most of the time its behind hills of mediocre filler content. atleast you can't go wrong with the mainline KH1-3

Kingdom Hearts:
I found that this one was pretty boring until the last few worlds, but those last few worlds were good. The room before the final boss and the final boss itself sucked though.

Kingdom Hearts Re:Chain of Memories:
words can't describe how much i loathe this steaming pile of garbage. save your sanity, watch the cutscenes instead of playing it.

Kingdom Hearts 358/2 Days:
one of the better stories in the series, gameplay is probably the best that could be pulled off on the DS.

Kingdom Hearts II:
My second favorite in the series. Easily the best playing game (god bless drive forms) and its story is great too.

Kingdom Hearts Birth by Sleep:
it's gameplay is good, shotlocks are fantastic, but there's practically no story until the ending, which was honestly pretty cool.

Kingdom Hearts Re:coded:
holy moly this one blows. still better than re:chain... but thats not saying much.

Kingdom Hearts HD: Dream Drop Distance:
flowmotion is fun as hell, although a bit broken. story is kinda dumb but it has its moments (AHEM TRAVERSE TOWN AHEM).

Kingdom Hearts 0.2 Birth by Sleep: a Fragmentary Passage
a good introduction to how KH3 functions, but its extremely short.

Kingdom Hearts x Back Cover:
i don't really know what to say about this one. at least they didn't make anyone who wants to understand kh3 play the mobile games. also the GOATS matt mercer and ray chase are in it so...

Kingdom Hearts III: THE GOAT THE GOAT THE GOAT THE GOAT THE GOAT THE GOAT

in all seriousness this game feels like an cinematic event/massive crossover and i'm here for it. the ending couple hours are PEAK.