Realistic, fun, team-oriented. The learning curve for people with previous FPS experience is short.
Gameplay. You have to be really careful to not get shot in the game, although once you get the idea that it's not a typical "runattheotherguy'sbasewithgunsblazing" type of FPS, it's quite easy, as the engagements are at considerably longer ranges than most first person shooters. It requires actual tactics.
The teamwork element is mostly focused around two main roles: machine gunner and demo guy - the rest are for pure combat purposes. The crouch system, where you can deploy your weapon on sandbags and other obstacles works beautifully.
One great feature of the game is the sound. Depending on the distance, shots will actually sound different, not just quieter or louder. This is a useful tool when judging the distance from a firefight.
The graphics are good for the weapons: everything is shown, the bullets, the shells, ect. They look wonderful. The infantry-focused maps look pretty nice, with graphics pretty much on par with BF2. However, the tank maps are not exactly spectacular, mostly just grassy hills with a few bushes and a hedge to note the edge of the map.
The difficulty is hard, but there is room to improve. The spawns are only a few seconds apart, so it isn't 20 seconds of play, 1 second of being killed, and two minutes of waiting, a la Counter-Strike (which is notorious for driving away new players).
At $25, you just can't go wrong.