I've played a little on my brother's BETA account on Matrix... I have to say so far I'm impressed for what stage the development is at.
The concept of the game, is that it's taking place after the 3rd movie, when mass people are starting to become "awakened". Basically, there will come a point where you have to choose sides, and the story follows with each side undercutting the other, with betrayal, promises of grandeur, setups, etc etc. There is the side of Xion, of course, which believes that there should be no AI interraction and seeks liberation from the machines. Then, there is the machines, where their belief is somewhere along the fact that if Xion took completely over it would upset the balance or something like that, which is why people would side with the machines. The odd man out is the Merovingian (remember the wine fanatic introduced in the 2nd movie?), whose motives aren't quite clear but they aren't sided with either Xion or the Machiens.
As far as I understand, the gameplay is decided by the actions of the PLAYERS... and will continue to evolve based on the actions of the players and what certain people do. Nobody knows if Neo's alive or not, or what even happened, but mass amounts of people started to "awaken" (ie, the player base). The game is the struggle for power of the 3 factions over control or extermination of the matrix itself.
The character models are well-detailed for this state in the testing, and the gameplay and combat is quite interesting, almost like a real-time and turn-based type setup... you'd have to play to really understand I guess. Basically the same as any MMO's combat system, but flashier moves and all that good stuff. Different "classes", like hacker, a few melee based classes, gun specialists, etc.
And I believe the levelup system is mostly through quests, not defeat of mobs. Not your traditional MMO in that sense...
Should be coming out in the Summer or Spring, but they keep delaying it.