Arma 2 has a 125 square mile map with better graphics than Crysis.*
Anything is possible nowadays. It's just a question of what is a practical priority for gameplay.
*in terms of realistic natural terrain and quality of models and textures. Crysis looks better once you drench it in visual effects.
Yes, Arma 2 has a massive game world. I just started playing that game and my jaw dropped because it doesn't have NO LOADING screens when you traverse the landscape. Pure streaming technology. The AI is one of the best I've ever seen in my life. For example, I got in a car and commanded a friendly AI to drive me from point A to point B. While I was in the passenger seat enjoying the beautiful countryside, this AI traverse about 200km through highways, towns, winding roads and bike trails avoiding all kinds of objects along the way. The travel took about an hour. The drive wasn't robotic or artificial. In other words, the AI was speeding, slowing down, stopping if there was an obstacle nearby and sometimes going off the beaten path to find a more convenient road. Nothing is scripted. When you kill an npc he will never respawn; he's body along with the blood decal will still be there all the time. The war is in real -time, in other words, while you are in a mission in one area your friendly troops are fighting 225km away at the same time. You can radio them to do duties for you in real-time. If you died, the war continues on without you. Indeed, this game is not player-centric. You probably saying what this has to do with the topic? Well, very much. It's easy to create a massive world such as Just Cause 2 but to have a level of advanced AI, not to mention the game calculating through out the map all ballistics being fired (bullet drop, wind deflection, damage to objects, calibre used) will bring Just Cause 2 fps to its knees. Arma 2 is a simulator so graphics, though surprisingly good and at times Crysis quality, is not its priority. People unfamiliar with Arma 2 want flashy Crysis-CoD style graphics but it's impossible for such a real-time open ended game world with such advanced mechanics and no loading screens to cater both things acceptably. There has to be a compromise somewhere.