I'm laying on my belly in the dirt, picks up my binocular, opens up the pretty huge control scheme and order my men to stand up, hold their fire, and keep quiet as we approach the village we're about to attack. One false move can erase my 40 minutes of planning the whole approach. Most people beg for realism in games but when it actually happen, many people simply find it to hard and complex.
Realism in arma means that your enemies are developed to kill you and not to amuse you. If you get shot in the leg you might have to crawl the rest of the mission if you don't get medical attention. You wounds never heal. Bullets drops and do not go straight. You can only take as much damage as your extremely smart enemies. Barely nothing is scripted.
There's no Run'N Gun heroics here. Enemies can shot you down with precision laying 400-500 meters away, hidden behind a bush. If you don't like the concept of totall military realism, and if you don't have the patience to learn the fairly complex control scheme, don't go for this game. Arma 2 requires a lot of patience and the game has a very long learning curve. When you learn how to play the game, all about the controls, and how to act in combat and set up tactics, you will probably enjoy it. The graphics and the game physics is amazing, as well as the seize of the map, the freedom to complete your objective almost however you want, the multiplayer mode, and the incredible ability to mod the game: there are thousands of mods for it out there.
The game also feature a Map Editor, which let you create your own missions and campaigns. It's pretty easy if you want to do it on the basic level - and really, really fun! One of the downhills with the game is that you'll need a pretty good computer to even run the game on normal settings. Buggs is also something you that is a problem - however- most of it has been fixed after release with patches.
It's really, really worth to try out in case you have a powerful computer, and of course, if you want a game that requires pure skill and tactical thinking. Forget about everything you've learned in battlefield or call of duty. This is as close to reality you can get in form of a video game. Arma 2 is finally an outstanding combat simulation game.