Silent Hill Origins is a prequel to the original game developed by Climax, first released for the PlayStation Portable and then given a port for the PlayStation 2. The game follows Travis Grady, a trucker who, along the way, stumbles upon a burning building and enters to rescue a badly burned girl. He passes out from the smoke and wakes up in Silent Hill before the authorities arrive.
Looking at builds that never came out is a great way to see where the original game might have gone if it had been released instead of the original port. A build of Silent Hill Origins (Zero) has apparently been spotted on Youtube. The Japanese build in question is for the PlayStation 2, which was never released. According to youtuber PtoPOnline, who posted it online, this is a fairly late build, dated February 5, 2008.
The build runs on PCSX2, an open source PS2 emulator. However, Silent Hill Origins reportedly had various earlier builds. Builds should have tested the limitations of the game and possibly explored different options.
The game is not the best in terms of graphics, but given that the original game was released for the PSP, it ported well to the PlayStation 2.