Other series inevitably lose money.
The popularity of Call of Duty makes it almost impossible for other FPS games to succeed, according Free Radical founder Steve Ellis.
"Nobody really buys any FPSes unless they're called Call Of Duty," said Ellis, speaking to Edge.
"I guess Battlefield did okay, but aside from that pretty much every FPS loses money. I mean, Crysis 2: great game, but there's no way it came anywhere close to recouping its dev costs."
Ellis coded the multiplayer components of GoldenEye on the N64 and later went on to set up Free Radical, the studio that created Timesplitters.
However, after failing to find a publisher for Timesplitters 4, the company came perilously close to going bust. Crytek bought the studio at the last minute, rebranding the firm as Crytek UK.
"I spent the whole of 2008 going round talking to publishers trying to sign up Timesplitters 4," Ellis explained.
"There just isn't the interest there in doing anything that tries to step away from the rules of the genre - no one wants to do something that's quirky and different, because it's too much of a risk. And a large part of that is the cost of doing it."
Timesplitters 4 has become something of a gaming Bigfoot. Despite the official cancellation, VideoGamer.com learned that the game was being shown off at last year's E3. Last week additional sources claimed to have seen the game running.
Ellis himself has shifted his attention to iOS, having set up a new studio, Crash Labs, with other Free Radical refugees. The company has so far revealed two of its projects – Flying Rocket Defence and Twist Pilot.