I have been playing with these game concept for the last few days and have done some minimal research but since I am lacking any real experience in this field I thought it would be better to consult people arround here
Basicly the idea is having several "battlefields" to which players could access and PVP. Game style would be FPS much like Unreal or Quake with arround 20-30 players per battlefield. I have been thinking using Unity in order to keep players away from downloading huge clients but still offering them some modern 3D grafics and the easiness to play directly through their browser. However Unity´s multiplayer capabilitiues are very limited so I looked up SmartFox2X. However the games listed on their website are far from being multiplayer FPS. Most are card trading or 3D chat room style games and I am not sure if SM2X would be good choice.
What is your opinion and experience?

