Obviously, the single player experience isn’t perfect. For one thing, why did it have to be single player? Many portions of the game, particularly the whole sniper sequence, seem almost tailor made to be played cooperatively, and this game was even released after other games like Rainbow Six: Vegas and Halo 3, which were both elevated beyond the sum of their parts by supremely entertaining cooperative modes. I understand that it obviously wasn’t the game the designers set out to make, and even if it were, it’s not exactly a simple feature to just drop into a game, but that doesn’t make me any less frustrated by its absence. Also, to reliably deliver its story, Call of Duty 4 is one of the most linear and heavily scripted high-profile first-person shooter experiences currently available. Contrasted with a game like Crysis, which is largely an open-ended shooter, allowing the players to solve problems in their own way but offering little in the way of story, the narrow hallway of trigger points that is the single-player mode of Call of Duty 4 may seem rather claustrophobic, but the developers clearly saw it as a necessary means to their end. Such issues don’t exactly detract from the experience of the game; they simply are the experience of the game. It is mainly only in comparison to other games that such perceived shortcomings are even apparent.

But while the single player campaign alone could surely have not sustained Call of Duty 4’s popularity for nine months, comparisons are also easy to come by in the multiplayer mode. After all, the basic structure of the entire portion of the game is lifted almost entirely from Halo 3. Deathmatch is Slayer, Domination is King of the Hill, Sabotage is Bombing Run, etc., but all first-person shooters are pretty similar, even if it isn’t always to this degree. The matchmaking and ranking also appear to at least be inspired by the Halo 3 system, but honestly, even if it weren’t such an easy and effective interface, it’s certainly one of the strongest parts of a very successful game, so the developers could certainly have borrowed worse ideas.

Call of Duty 4 is no carbon copy, though, as it has plenty of features to call its own. Perhaps most important to the game’s popularity are the elements of permanence in the multiplayer, and it goes far beyond the ranking of Halo 3. Players unlock game modes, weapons, optics, camo patterns, perks, and other tools to further personalize and take ownership of their character, tangibly demonstrating the hours they’ve put into the game both in the form and functionality of their avatar. This leaves gamers simultaneously striving for their next goal and eager to utilize unlockables they’ve recently earned. This leads to some “walled garden” issues, however, making it more difficult for new players to enter the game, as more experienced and more skilled players also have better weapons and more perks, making Martyrdom and the M60 the bane of newbies’ brief existences between frequent spawns. This is further exacerbated by the slippery slope created by kill bonuses like the UAV, air strike, and helicopter, which further empower those with the most kills. The spawning system also appears to be perfectly willing to toss recently dead players back to the same air strike that previously killed them, further wrecking chances of a comeback. To its credit, such demonstrations of superiority may simply entice new players, showing them the business end of what may yet be theirs if they only put in the time. MMOs use such tactics to keep players grinding, and they appear to work at least as well in the context of a shooter.

Besides, it seems that despite Call of Duty 4’s obvious multiplayer inspiration from Halo 3, Bungie is not above recognizing that which Call of Duty 4 did better. Bungie staff recently admitted that they could particularly learn from Call of Duty 4’s single player theatricality and multiplayer experience rewards. Clearly, the lessons learned by Activision and Infinity Ward have been internalized by the rest of the industry as a whole and will continue to be so for some time in the future. This can only be to our benefit as gamers.