I recently had an idea of a multiplayer focus game that is a combination of the multiplayer aspects of Assassin's Creed: Brotherhood, Bad Company, Left 4 Dead versus mode,Team Fortress 2, Rainbow Six, Splinter Cell, and I guess Crysis 2.
There are multiple classes to play as that play COMPLETLY different, and you all are set in huge maps and obviously have to kill eachother. It would be a dark, sort of scary game, or realy violent with the fear of sneaking death. Each class would offer a different playstyle. Soldier would be more Rainbow Six/CoD type, where it is action oriented but requires team tactics. These guys are frontline and would have many gadgits to fight against the more technical classes.
Juggernaught is huge, slow, and powerful, but easy to sneak up on. Actually assassinating one is more difficult than just stab in back though. They are powerhouses to be feared, but they are always obvious to everyone. Think Big Daddies on steroids.
Assassin would be stealth based. More Splinter Cell style. You spentd your time in the dark, good players never being known until they kill. Soldiers require predator style approach, while attacking a Juggernaught is more difficult, since assassinating one requires getting on them, and things may get slighlty Shadow of the Collossus...but obviously happen within a couple of seconds.
There would be more variety within these types though, and would be cool if it was many players in a large battle as opposed to 8 v 8.
This game is intended to hypridize tons of games together obviously.