In modern gaming, many developers believe that multiplayer is king. With MOBA titles such as DotA and League of Legends breaking user records and filling stadiums for tournaments, it's no surprise that other games have been given an online multiplayer focus. Even story-driven games like Dragon Age: Inquisition have had additional multiplayer elements.

Often, these multiplayer modes have been added to give the games in question longevity, or as an attempt to push sales by offering something to a larger market. Publishers have looked to give players the choice to play in co-operative missions like BioWare did with Mass Effect 3. However, not all is as it seems, and a number of high-profile games have instead seen a dramatic drop-off in their PC player base over a very short amount of time.

One of the publishers who has suffered worst with this trend is Ubisoft. At the end of 2014, the publisher released a pair of extremely high-profile titles, with single player game modes enhanced by the multiplayer experience. One of these games was Assassin's Creed Unity, one of the most hyped games of the year. The publisher pushed the title's four player co-operative mode in the run-up to release, and at the very least the game was commercially successful - between Assassin's Creed Unity and Assassin's Creed Rogue, Ubisoft sold 10 million units overall.

Unfortunately, that success has failed to carry over into any kind of sustained PC player base or longevity. Assassin's Creed Unity had a tremendous spike of players upon release, with a peak of over 12,000 concurrent users the weekend after the game launched, but that user base dropped away dramatically. According to SteamDB, the concurrent user peak dropped to approximately 3,000 players within only two weeks. Six months later, and the Ubisoft title is lucky to get 500 players.

It's a similar story for The Crew. The racing title again topped 12,000 concurrent users upon its December release, but that player base was halved within a fortnight. The title has fared better with retaining players, but again has dropped to the 500 player mark based on current figures. With The Crew initially sold as the go-to racing MMO, with wide-ranging multiplayer features and faction vs. faction racing, such a drop in concurrent users is bound to be a disappointment.

At least, for Ubisoft's sake, both games were not entirely multiplayer-centric, with a wide array of single player features. The same cannot be said about the Call of Duty series, where fun, popular multiplayer combat is their bread and butter. Unfortunately for Activision and Sledgehammer Games, Call of Duty: Advanced Warfare has failed to live up to the franchise's history, even though the game fared positively with critics and topped the bestselling games list of 2014.

Advanced Warfare has even fared admirably when looked at separately from the Call of Duty series, hitting nearly 10,000 concurrent players on May 3 thanks to a free Steam weekend. Unfortunately, the game has suffered when compared to fellow Call of Duty titles. Advanced Warfare's PC player base is distressingly similar in size to that of Call of Duty: Modern Warfare 3, and nearly half the size of Call of Duty: Black Ops II, a game two years its senior.

Sledgehammer Games does have some positives to look for, however, as at least Advanced Warfare attempted to make some changes to the Call of Duty formula. The title stepped away from some of the stale elements of the series, pushing into a speculative future, and still manages to be a regular factor in Steam's top games by player count. The developer can also look at its most recent CoD predecessor for a silver lining: Call of Duty: Ghosts may have outsold Advanced Warfare, but the Infinity Ward title has dropped below even Modern Warfare II's online player base.

There is also one other positive to be found for the Advanced Warfare team: at least the Call of Duty title has not seen the kind of dramatic drop-off that has plagued one of the most highly anticipated multiplayer games of the decade. The game in question has seen its player base drop to less than 2,000 players in less than three months from its release. That game is the Turtle Rock-developed Evolve.

Evolve is a surprising source for what may be the most egregious case of player drop-off in recent memory. The title had pedigree behind it, with Turtle Rock Studios responsible for the hugely popular Left 4 Dead series. Meanwhile, the game had an impressive open beta period with over 2 million games played, and painstaking balance testing to make sure the asymmetrical multiplayer title gave both hunters and monsters alike a good chance of success.

Unfortunately, it looks as though all that effort has failed to create a long-lasting experience for adopters of the title. Indeed, there were signs as early as March that Evolve was facing a crisis in its player base. The results now are astounding, with the 2K-published game struggling to even make 1,500 concurrent users per day. With figures like that, it looks as though Evolve is facing extinction.

Just what has turned players away from these games? It's perhaps easiest to pinpoint what went wrong with Assassin's Creed Unity. The title was plagued with problems at launch, with a number of game-breaking glitches and with some players unable to even play the highly-anticipated co-operative mode. Even though Ubisoft offered up patches to try and fix the title's multiple issues, the damage was already done.

Multiplayer aficionados may have also felt let down by The Crew. The initial faction vs. faction races never quite materialized as they were meant to, losing the title one of its initial unique selling points. In the end, players were left with an interesting and adventurous racing title, but not one that quite lived up to the high expectations set and that therefore did not have the longevity of a multiplayer hit.

Call of Duty: Advanced Warfare struggles with a different set of issues, as the Call of Duty franchise has been facing a gradual decline in popularity over recent years. Although the series is still one of the industry big-hitters, there has been a backlash in the gaming community against Call of Duty in general, with complaints that the franchise has been growing stale. Advanced Warfare may have been hit on both sides, with the gradual decline in CoD popularity affecting sales and hardcore fans failing to gel with the title's changes to the gameplay formula.

The case of Evolve is much more intriguing, however. The game was built as an ingenious addition to the multiplayer game roster, received a positive reception to its beta test, went gold in January, and received rave reviews upon release. Where, exactly, did it all go wrong?

There have been some suggestions that the business strategy of 2K Games pushed players away from the title. Crave Online states that the exorbitant DLC costs could have been a factor, with Evolve receiving criticism over an incredible $136 worth of day one additional content. At times, it certainly seemed as though 2K Games was placing a little too much focus on giving fans extras to purchase, such as the limited edition $750 goliath statue. Gamers may have already lost trust in the title before its release.

There is, however, another explanation for Evolve's failure to adopt a strong, long-lasting player base. There have been some concerns that the game lacks replay value, with a limited number of maps and game modes. It's not only the game modes that are limited too - Evolve also works best in a very specific set of circumstances, with the hunter team requiring almost constant communication to succeed in taking down the monster.

As it stands, Evolve's problems go deeper than a simple fan reaction to business models. Evolve has done well enough commercially for Turtle Rock to count it as a financial success, but lessons will need to be learned for any additional content or sequels in the works. With Left 4 Dead 2 still hitting 10,000 concurrent players a day, perhaps the studio needs to look back at what made its previous franchise so successful.

Sources: SteamDB (1), SteamDB (2), SteamDB (3), Steam Stats, Crave Online