Best way to play them is just the order they were released . BBS might be the prequel to the main series but it ' s best appreciated after you ' ve finished the games that came out before it . The games do have official numbers , they ' re just never used in the marketing . There ' s a reason the upcoming collection is called 2 . 8 . They got it from adding up the numbers of the 2 games and the 1 cinematic that are in the collection . The cinematic basically tells the story of the mobile game , along with a little extra new footage , since you can ' t really port a smartphone game to console . The mobile game is marked with the Greek letter chi which looks like an x . So if you see an x it means chi not ex . On how the name of the collection was determined , Nomura stated that Kingdom Hearts Dream Drop Distance is considered number 2 . 6 in the series since it follows the events in HD 2 . 5 Remix , and the games , with the absence of Sora , are considered 0 , while Birth by Sleep is 0 . 1 , thus resulting in 0 . 2 for A Fragmentary Passage . When added together , the numbers total 2 . 8 . So 2 . 8 is gotten by adding 2 . 6 0 . 2 0 . 2 . 6 is Dream Drop Distance . 0 . 2 is the brand new game , A Fragmentary Passage . 0 is the cinematic based on the mobile game , x . Kingdom Hearts 2 . 8 will be coming out on PlayStation 4 so you will be able to play Dream Drop Distance on it even though that game originally came out on the Nintendo 3 DS . As Nomura said , Birth by Sleep is considered 0 . 1 since it ' s the prequel game before 1 . A Fragmentary Passage is the continuation of the events at the very end of Birth by Sleep , so it ' s 0 . 2 . You might be a little confused though since A Fragmentary Passage was supposed to be the prologue of KH 3 because it takes place right before KH 3 . That ' s because the events of A Fragmentary Passage take place over the course of 10 years . They start long before Sora begins his journey and don ' t end until right before KH 3 . Part of the reason they do these collections is to help consolidate the series . You ' re right that a lot of the games came out on handheld consoles originally . That ' s why they release these collections . You can play Chain of Memories and Birth by Sleep on your PlayStation if you play the collection they are in . I don ' t remember if 3582 Days is playable or just a cinematic but the cinematic would be enough to understand that game .