I have been awaiting Armed Assalt for a long time as a fan of Operation Flashpoint and was not disappointed.
The game is very similar to Flashpoint in terms of its control interface (although some controls have been changed to incorporate a lean function), so Flashpoint fans should have no trouble playing Armed Assault. For those that are not, the controls are for the most part very simple and easy to learn, only becoming difficult when the player attempts some slightly more difficult tasks, such as flying a helicopter (which is mch more difficlt than in Operation Flashpoint).
Graphically, the game is very flexible. Most lower-end PCs that meet the reqirements run the game quite comfortably on low settings, and players with performance machines are in for a visual treat, with extreme-length draw distances and NPC models that are a far cry from the blocky mannequins of Flashpoint. I would argue that on the highest graphics settings, Armed Assault looks much better than other games such as Battlefield 2142.
The gameplay itself is certainly an aquired taste, as one or two bullets from an enemy will have you loading up again, but as long as you keep to the ground and move safely, you will survive. Operation Flashpoint was notoriously difficult, and this is the same in Armed Assault, except that Armed Assault has been blessed with a save function, allowing you to save your game wherever you please, preventing the annoyances of almost completing a mission and having to restart just moments from completing a mission.
The game world itself is huge, as you are playing on a 400 square kilometre island, and the game features dozens of different vehicles to use, from the AH-1 attack helicopter to a farmer's tractor.
Unfortunately, there are some problems with the game. On some single-player missions, bugs in pathfinding will result in incompletable missions, such as one where you are required to board some tanks; upon doing so the tanks will drive up the road and then turn back to the start and wait...forever. The problem of vehicle pathfinding is shown when, in some missions, driver NPCs will turn randomly off the track, reverse, and then continue on their way, for no apparent reason.
Furthermore, the maps are chunky and more dificult to interpret than in Operation Flashpoint, and mission briefings are poorly translated and written. Some of the enjoyment may be removed because of this, as well as that Bohemia Interacive, the developers, have removed the 'characters' in the story, although this does place further emphasis on the greater conflict of the game and give it even more of a 'simulator' feel (which is what the game is about).
Overall the game is highly enjoyable, in both single and multiplayer, in spite of the minor bugs, and I recommend it to anyone, unless of course you strongly disliked Operation Flahpoint. The game would have a higher score if the game had been released with more polish. Patches will certainly be released, and make the game an even more enjoyable playing experience.