Weak guns, brain-dead AI, and a short campaign spoil what was a fantastic idea for a game. There is still fun to be had in Raccoon City however.
Resident Evil: Operation Raccoon City is a third person shooter that really needs to be played in four player co-op mode to be appreciated. However, unless you enjoy going through the same levels time and time again looking for secrets to collect, you will quickly tire of the campaign which lasts only about 4 hours (and can easily be beaten in 1 once you know what you're doing) as there are only 7 levels.
The basic premise is during the events of RE2 and 3, the Umbrella corporation has sent you and your squad to wipe out the town and any evidence tying them to the outbreak. Several cut scenes feature events from the original games and are pretty interesting if you've played those. In addition to fighting the infected that roam the streets, the government has sent in the military to stop you and recover the evidence you are out to destroy. You also encounter some of the protagonists of the original games like Leon and Claire as you progress.
ORC commits one of the biggest sins a shooter can; the weapons just feel weak. It doesn't matter which gun you use, they all feel like they fire rubber bullets (unless you're playing on easy). On the highest difficulty setting, the unarmored heads of the military foes can take a half a dozen shots from an assault rifle before finally blowing up in a shower of blood. Many of the boss battles feature big baddies (such as the Nemesis and Tyrants) but you can't really tell if you're doing any damage to them (there's no life meters and they don't really react to the bullet hits) which makes the encounters feel tedious. Worse, there are encounters where you are not able to injure your opponent, you are simply supposed to advance on them until a cut scene triggers, but you don't know that so you sit there and fire at them for half an hour before someone in your party gets tired of it and goes all LEROY JENKINS and charges them. Ugh.
Each of the members of your squad has unique powers that you can unlock throughout your playthroughs (the XP builds in both campaign and multiplayer modes, so you don't need to do one or the other to level up, but you can get much more XP out of the campaign especially in areas where zombies spawn infinitely). Unfortunately, these powers are fairly uneven and some of them just outright suck.
The AI is so bad, that there really is no reason to play single player unless you're just boosting your XP to unlock some power or gun. Seriously, the single player experience sucks. Don't bother with this game unless you're going to play with friends. Which brings us to multiplayer. There are several multiplayer modes which are variations on classic MP modes. For instance instead of capture the flag, there is a capture the G virus mode where a single vial spawns in the middle of the map and both teams race to recover it and bring it back to their base. You're not just fighting the other team either, tons of zombies also are present to make your job (and your opponent's) tougher. One of the most satisfying ways of dealing with your foes is to wound them enough that they "bleed" causing the surrounding zombies to frenzy and focus on them. Unfortunately, as bad as the guns feel in the campaign, they feel even worse when trying to target a human player instead of the brain-dead AI.
The story is fun, if a little frustrating, to play through the first time with friends, and some people may enjoy the multiplayer more than others, so ultimately this is a rent, mostly due to the extreme shortness of the campaign.