While we know Mass Effect 4 is being developed by BioWare Montreal we don't know much about it beyond the fact it's being developed on the Frostbite 3 Engine; however, many players felt the original series met with a flawed conclusion which resulted in BioWare releasing a free 'Extended Cut' DLC to address fan complaints.

But the ending which made it into Mass Effect 3 wasn't always what BioWare had envisionsed.

Drew Karpyshyn, the lead writer on Mass Effect and Mass Effect 2, has detailed how he might have ended the Mass Effect trilogy had he stayed at BioWare.

In an interview transcribed by Eurogamer Karpyshyn said the ending he had planned "wasn't super fleshed out" but relied heavily on Dark Energy which several characters alluded to in Mass Effect 2. Tali's loyalty mission in that game, for instance, involved visiting a planet whose sun had become dangerous due to the presence of Dark Energy.

"Dark Energy was something that only organics could access because of various techno-science magic reasons we hadn't decided on yet," Karpyshyn said. "Maybe using this Dark Energy was having a ripple effect on the space-time continuum.

"Maybe the Reapers kept wiping out organic life because organics keep evolving to the state where they would use biotics and dark energy and that caused an entropic effect that would hasten the end of the universe. Being immortal being, that's something they wouldn't want to see.

"Then we thought, let's take it to the next level. Maybe the Reapers are looking at a way to stop this. Maybe there's an inevitable descent into the opposite of the Big Bang (the Big Crunch) and the Reapers realise that the only way they can stop it is by using biotics, but since they can't use biotics they have to keep rebuilding society – as they try and find the perfect group to use biotics for this purpose. The asari were close but they weren't quite right, the Protheans were close as well.

"Again it's very vague and not fleshed out, it was something we considered but we ended up going in a different direction."

Some fans have looked on Karpyshyn's original ideas as a more coherent ending than the one which eventually made it into Mass Effect 3 from Mac Walters.

"I find it funny that fans end up hearing a couple things they like about it and in their minds they add in all the details they specifically want," Karpyshyn comments. "It's like vapourware – vapourware is always perfect, anytime someone talks about the new greatest game. It's perfect until it comes out. I'm a little weary about going into too much detail because, whatever we came up with, it probably wouldn't be what people want it to be."

You can listen to Karpyshyn's full interview with Video Game Sophistry here in which he also discusses a number of other ideas which never made it into the Mass Effect series.

Mass Effect 4 has no release window or launch platforms as of yet and the next confirmed game from BioWare is Dragon Age: Inquisition which is set to be released in Autumn 2014.

The game's executive producer, Casey Hudson, has previously asked what people want from the game while Mac Walters has confirmed he is working on the title. Some members of the Dragon Age: Inquisition team are also involved in the development of the next Mass Effect.

Both Inquisition and Mass Effect 4 will share "core systems" it has been revealed. Mass Effect 3 was released in March 2012.