It feels like the world may never see another TimeSplitters – the humour-infused first-person shooter series from defunct British developer Free Radical Design.

It’s a huge shame – 2000’s TimeSplitters, 2002’s TimeSplitters 2 and 2005’s TimeSplitters: Future Perfect were some of the best shooters of their generation, made by many of the same team behind the legendary 007: Goldeneye. There’s not been much like them since.

It’s widely known that a fourth TimeSplitters was once in development – firstly at Free Radical Design in 2007, and then again after the studio rebranded as Crytek UK. But nothing ever got far enough to be announced.

Details on what a TimeSplitters 4 might have looked like are thin on the ground, but this week a huge cache of concept art has popped up online via Reddit, giving us perhaps our best ever glimpse at some of its characters.

There are characters from various settings – Ancient Greece, 1950s USA, swashbuckling pirates – plus the usual range of mutated people, nuns and monkeys.

Eurogamer understands the images mostly date from 2007 until early 2009, during a period that TimeSplitters 4 was being worked on in pre-production and while the studio was busy with its Star Wars projects.

Why did TimeSplitters 4 never see the light of day? It comes down to the project never finding a publisher, staff later said. The negative reaction to Haze, a PlayStation-exclusive shooter with none of the silliness of TimeSplitters, and the fact its characters were too diverse to market easily.

“TimeSplitters 4 was in the very early stages of development when Free Radical went into administration,” TimeSplitters co-creator Steve Ellis said in a 2012 interview with GamesTM magazine. “A small playable demo was shown to several publishers, but it didn’t attract any publishing deals.”

Said studio boss Karl Hilton: “Publishers would ask what happened with Haze. We were the company that made a series of high-rated shooters and then we had released Haze, which wasn’t as well received. This worried them.

“Secondly, their marketing person would say something along the lines of, ‘I don’t know how to sell this.’ The unanimous opinion among all publishers that we pitched TimeSplitters 4 to is that you can’t market a game that is based around a diverse set of characters and environments – you need a clear and easily communicated marketing message, and TimeSplitters doesn’t have one.

“Perhaps they are all right. Perhaps this is why the previous games in the series achieved much more critical success than commercial success. For these reasons, one by one they all declined to sign the project.”

Concept art for Free Radical Design’s cancelled Star Wars Battlefront 3 and 4 projects has also recently surfaced online. What could have been.