Its a whole different game when you play this one online.
You are judged in Campaign mode at the end of every level, and might I say rather harshly. You are awarded up to 3 stars per level based on your performance and you use these stars as attributes, they help you get better at killing, surviving, and buying better weapons. The most you can gain per level is 3 stars, I only managed to gain 3 stars twice out of the entire game, that includes my third time through it with a buddy on co-operative mode. On average I would gain about 1 star and occasionally 2 if I did really well. I just think they aren't to nice when it comes to evaluating your performance, but ok you don't really need to buy every weapon and upgrading your attributes, for the most part, doesn't help you immensely, just a little bit. It wasn't even until I was neraly 2/3 the way through the game that I learned how to control my CPUs and how to get them to exchange health and ammo with me. Which reminds me, ammo was an issue in this game, sure a realistic effect but in some levels you seriously have got to watch how much ammo you use. I was down to killing people with my knife for the last 10 minutes of one level where I was underground in a cave system. One more thing about the Campaign mode, the enemies would only appear after you prgressed to a certain point in the level usually, which reall diminished the depth of strategy that that I could use to beat each level. For this game trying to be really realistic and all i would think that having enemies in predetermined places or even on patrol would be better than giving them teleporters.
Now lets talk about the multiplayer, this is cherry on top of the cake, this is the main reason why you would want this game. You can play with just a few people, you and 1 buddy if your just playing multiplayer and you onlu have 1 TV and no multitaps. You can bring in a total of 3 buddies to play multiplayer with if you have 1 TV, 4 controllers, and 1 multitap. However, even with 4 human players, most of the levels on this game are just too huge and they don't downsize them for mutiplayer, instead they give you the option to increase each players movement speed, which I don't like it to be any higher than what is normal, after all, my soldiers don't use steriods.
The online part of this game is actually a blast, you have a huge arsenal of weapon that you can choose from and 4 different character types that you can play as. The sniper, my preference, has about 8 or so gun he can use, ranging from rapid single shot weak snipers (such as the PSG) to deadly 4 shots per reload, slow reload time and slow firing rate snipers (like the MRC Tactical, my fav.). The assault dude is the average gunner who has various types of mahcine guns, many weapons with high firing rates but usualy close distance weapons and not good at all at snipeing with. These guys boast a M203 on nearly every kind of machine gun they use if they want one, and a M203 is a built in grenade launcher, yes its sweet, 3 shots per life. You also have the heavy artillery dudes who carry stuff that looks as painful as a 50 Cal (speaking of whihc there are stationary 50 Cals that you can take control of during most levels, basically a 1 hit kill weapon with an incredible firing rate), these guys also get 1 rocket launcher shot per life, this is the type of guy for you if your new to this game or if you know you couldn't hit the broad side of a barn if someone pointed you in the right direction. Lastly there is the faithful medic, these guys usually carry a silenced and very accruate sub-machine gun with a incredible firing rate, medic are given the special ability to heal or revive teamates. Up to 32 player can being playing in 1 game, which makes for some awesome Team Deathmatch games or Capture the Flag games.
Overall this game was dissapointing in single player, but made up for it in its online mode, speaking of which you can earn medals in the online mode and ranks, both based on acheiving certain feats in the game and your average kills per death ratio.