Microsoft is very excited about unified development for PC, XBOX and Mobile. They’re talking about the exact same game, with minor adjustments, on all 3 platforms. Most people can see some kind of fault with that reasoning. They can’t.
One size fits all tends to end up with whatever the worst platform can handle. This kind of works from XBOX and PC, with the XBOX being a crappy PC and PC developers being used to develop for crappy PCs. It doesn’t exactly work cause controls on a PC are much richer than on an XBOX. And console games are simpled down versions os PC games anyway.
But let’s face it, a Snapdragon mobile phone isn’t exactly a crappy PC. It’s not even a PC, it’s just a low power CPU with lowend 3D graphics. You’ll end up playing on your 2000USD PC a game your phone can render.
What works is having, not versions, but aspects of the game. You play some parts on the XBOX or the PC and some parts on the mobile. Example, on an adventure game you play some wicked 3D combats on XBOX and do your adventuring on the mobile taking advantage of all the nice things a mobile has, such as a touch screen and mobility. This isn’t rocket science, Nintendo did this with Zelda on Gamecube+GBA (expect the cable made it awkward), and in the end what you need for a compelling game is making the best experience possible all around, not go easy on the developers.