Killzone: Shadow Fall could have been 290GB

In Europe, the final version of Killzone: Shadow Fall is a respectable 39.7GB in size. It turns out that that's nothing compared to what it could have been. At one point it was 180GB and, if changes hadn't been made, might have been as hefty as 290GB.

Eurogamer has chatted with Guerrilla's technical director Michael van der Leeuw about lots of technical things that will get spec fans a little hot under the collar. It turns out that textures are to blame for the game being so big.

"The bulk of it is textures," van der Leeuw told me. "I think we're probably a lot larger than the other cross-generation games, because we have no assets that have been made to a lower spec." The size also has something to do with Shadow Fall being a much more open world than previous Killzone games. "The surface area, I'm just guessing here, must be five to ten times bigger than Killzone 3 was."

Killzone 3, funnily enough, was bigger than Shadow Fall by a couple of gig. Guerrilla began work on the next-gen follow-up using the same methods of duplicating textures for each level and including separate high-quality videos for different language. "

"I think at some point the disc image that we were generating was around 180 gigs," said van der Leeuw. "And if we would have put all the levels in, which we didn't, because then the disc image generator broke, it would have been around 290 gigs of data.

"So we had to completely re-architect how we deal with data. And we did a lot of work - this is actually something I'm extremely proud of - to optimise our disc access pattern. Sony made special libraries for us because we were the first ones hitting these sort of problems. I think it's something that a lot of people will need to be doing in future."

Van der Leeuw also spoke about PS4's PlayGo system, which allows you to start playing while the game is still downloading. He thinks that with a good connection you'll be able to get the first 7.5GB, play while the next level downloads, then get through that in the space of one evening. It's not perfect, but until a better solution is found it'll have to do.

"I think next time around we'll see if we can design something that doesn't jeopardise the game that will make it even friendlier," said van der Leeuw. "But I think all things considered, this being launch and we've got like 2 minutes 44 from disc to the first level and no installs, I think it's already a massive improvement over previous generations."