[quote name='mweav067']I own Birth By Sleep, and I've even played a good 10 hours of the one storyline. I intend to get back at it this summer.
The 3DS title is only 26 hours long? I may wait for a price drop knowing that... That is way too short for dropping $40 right away.[/QUOTE]
Not sure how long you typically take to beat a KH game, but I spent like 29 hours on KH2, 27 hours on Re:CoM, and 35 hours on Birth by Sleep but only because I spent a lot of time grinding and synthesizing new commands. Generally speaking, all KH games can be beaten in 25 hours or less if you just stick to the main story -- this game is no different. And let's not forget I still haven't tried out the coliseum in Traverse Town, nor have I fought any of the secret bosses (which are probably post-game content).
EDIT: So I finally beat the game, and what a crazy last couple of hours those were. The part that I thought was the ending turned out to not be the ending, and then the game managed to fool me a second time. Anyway, the reveals at the end are incredible. This is an absolute must play if you've been following the series. I ended up clocking in at 29:17 hours -- right up there with the series average.
[quote name='clay_bones']I have never played a KH game. Is this a good game to start on? Where does one begin?[/QUOTE]
Ideally one begins at the beginning and proceeds through the series in order of release, but KH1 is a decade old at this point and the gameplay is pretty clunky and bare-bones. Not sure how fun it'd be for someone who doesn't have some nostalgia for the game.
As for KH3D being a good place to start... it depends. The overall storyline is actually pretty far removed from the main quest, which is just 2 kids going through a bunch of Disney worlds. Occasionally you're treated to a cutscene where you won't have any clue what's going on, but those cutscenes aren't as frequent as the Disney cutscenes (that is, until the final world, where the game starts laying the plot on you pretty heavily).
The game also has this memoir system. After certain events throughout the game, you unlock a plot synopsis for one of the other games in the series (in chronological order I believe, so Birth by Sleep comes first, and afterwards they just follow the order of release). Not sure why they couldn't just unlock those for you from the get-go, but hey, at least they tried to make the game more accessible to newcomers.
I'd say it's a pretty decent standalone game if you're just looking for a good hack 'n' slash RPG experience for your 3DS, but it's kind of a weird jumping off point if you wanna get into the series as a whole. I really would recommend you start with KH1 or KH2 in that case. Birth by Sleep works as well because it's set 10 years before the first game, but eventually you're gonna need to know what happened in KH1 and KH2.
If you just want the "KH crash course", I say play through KH2 and Birth by Sleep, and you're pretty much set for KH3D and any other potential sequels. Whatever knowledge you're missing will fill itself in over time, or you could do some reading on the KH wikia. I just think KH2 and BBS are way too good to spoil them.
Oh, and here's the KH timeline so you have a better idea how these games all connect:
Keyblade War (as of yet we don't have a game covering these events)
Many, many years pass
Birth by Sleep
10 years pass
Kingdom Hearts I -- KH 358/2 Days starts about 2/3rds of the way through
Chain of Memories -- KH 358/2 Days continues
Kingdom Hearts II
Re:coded
Dream Drop Distance