The Crossing

Ever heard of this upcoming game....no?
Shame on you, it looks awesome.

By Arkane Studios, the developers of Arx Fatalis and Dark Messiah of Might and Magic, The Crossing is an upcoming first person shooter that fuses single and multi-player gameplay.
Made with the assistance of Valve and under the Source Engine.
The game incorporates the idea of parallel universes, and is set across two vastly different renditions of modern day Paris. In one, which shares many aesthetic similarities to our own, Paris has descended into anarchy following the collapse of government. In the other, the timeline diverged in 1307; where instead of being disbanded, the Knights Templar seize control of the French crown. The story will take the player across both universes.

So far, the game is ony announced for the PC, but, guess what, even the trailer only mentions that platform, but teamxbox found this..

What is exactly "cross play"? Well, imagine that in Gears of War, which featured drop-in/drop-out co-op for a friend to take on Dominic Santiago, any Xbox Live player could either take the place of a Locust or a Gears squad member while you are playing the campaign mode. Arkane Studios explains that The Crossing is a first-person shooter that allows players to take on any NPC. That sounds to me like next-generation multiplayer

So, The crossing is a PC/360 game

Trailer: http://www.gametrailers.com/player/29728.html

 

Assassins Creed...FPS style