Resident Evil: Revelations to everything except Vita because of the portable's screen format size and lack of surround sound. Those were the reasons given by Capcom product manager Mike Lunn on the PlayStation Blog, following the news of the 3DS game's impending arrival on PS3, Xbox 360, PC and Wii U.
Responding to a comment querying the lack of a Vita port, Lunn said, "When we were developing Revelations for new platforms we really wanted to hone in on the experience you get with a large format screen, surround sound, etc. This type of setup really helps players get sucked into the horror vibe and enjoy the game to its fullest extent."
That's all good and well, except for how Revelations was initially made for the 3DS and its not-so-large screens. Lunn went on to address that in another comment.
"3DS and PS-vita infrastructure let alone developing games for them are extremely different beasts," Lunn noted. "Even just the screens as you mention are completely different resolutions/functions."
Capcom's reasoning aside, that leaves the Vita without a Resident Evil game compared to two on its rival handheld, so we can understand frustrations. On the plus side, a lot more people get to play the popular 3DS game when it hits other platforms on May 21.