This game is the best underrated game i have ever played.
A very interesting aspect is that what you do in a level effects what you may do in another level. Maybe there is a helicopter that is making you life hell. So you go to a map, destroy the helipad and then there is no more helicopter for the rest of that level. You dont necessarily have to complete every map when you complete cetain objectives.
One of my personal favorites with the game was just lobbing grenades at my enemies, their bodies would sometimes launch 40 feet in the air. Maybe not the most realistic scenario, but a fun nuance nonetheless.
Graphics i think are not what make a good game. Graphics are merely a bonus to me. This game does not fall short, in light of the next generation of course this game is not up to par. However, the models are smooth, the enviroments are beliveable, and there isnt anything that would strike someone as ugly.
Overall, this game is a must for tactical shooter fans. Its a little more complicated and childish compared to other shooters, but when i think of good videogames, and interesting concepts i think of this game.