It sounds like a big demo
Odin Sphere: Leifthrasir is coming along nicely, and Vanillaware is keen to expand upon some of the new content included in the re-release. By completing the game once you’ll unlock “Xtra New Game,” which allows you to retain all of your data but restart the game on a select difficulty. Then you have “Hell” difficulty, which you can pick right off the bat without unlocking it. There’s also a 30-round boss rush mode in tow with the ability to choose any character at will.
Also, Japan will be getting a demo on January 8, and it apparently features all five characters. If you happen to have a Japanese PSN account, go ahead and give it go — you won’t regret it. Or you could forgo the demo altogether, as Leifthrasir is launching in Japan on January 14 on PS3, PS4, and Vita.