"Now with the budgets being so much higher you can't make a game for less than eight figures anymore."
Despite this, the TimeSplitters series continues to enjoy a loyal following of fans, many of which continue to campaign for a fourth game regardless (its biggest campaign is still taking place on Facebook).
As for what Ellis would like to see in TimeSplitters 4 were it to ever see the light of day, he's got a few ideas:
"One direction we wanted to take it in was to increase the differentiation between the different characters I think that was one of my key goals for it...to make it less than they are just different skins with slightly different attributes but to give them genuinely different abilities. I think that would be good."
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But its hard to say if enough people would use it to justify it, and these days cost is everything. It's always about the cost."
The gaming industry might have reached Hollywood proportions now, but if another GoldenEye ever happens, will it also be of British design?
"There's been a history of a lot of big things coming out of the UK," says Ellis, though he admits that getting things off the ground can be tough, and with so many of the big publishers waving stacks of cash across the pond, it's even more difficult for British developers.
"As a British developer I've often found that it's hard to find investment from other countries," he says. "Particularly if you're talking to American publishers. They'd much rather spend money in America. They like something that's on their doorstep that they can go and see what they're doing."
But far from being turning his back on the industry Ellis has found a comfortable new home on mobile, where he now develops for Crash Lab, the team behind game Twist Pilot. "From a development point of view iOS is the best platform I've ever worked on," he says. "It's just so good to work with. The whole Mac ecosystem, I'm a total convert on that, I don't have a Windows machine anymore."
It's strange to hear these words come out of the mouth of someone responsible for some of the biggest console games of all time. But Ellis learned that while riding the wave of critical acclaim was well and good, it was always going to be a short ride without the backing of the masses.
"It seems that people want games like COD [Call of Duty]," says Ellis. "I've never been a big COD multiplayer gamer, I have enjoyed the single player campaign."
"I don't begrudge them their success. It's just a shame that there isn't room for something that doesn't take itself too seriously."