It's been a while since anyone has heard from Guerrilla Games. The studio has kept quiet since Killzone Shadow Fall was released alongside the PlayStation 4 launch. Apart from some rumors about an upcoming project, nothing has been revealed about what the studio's been working on.

That said, E3 2015 isn't all that far away — and if the show is known for any one thing, it's big reveals. With Sony's holiday lineup looking a bit sparse in terms of exclusives, it makes sense that the publisher would play its hand close. Sony needs to wow gamers at the show, and one way to do that is revealing a big surprise exclusive during its press conference.

It's starting to look like said surprise will come from Guerrilla Games. Just days before E3 2015 is set to begin, the developer quietly joined Twitter, while simultaneously releasing a new piece of concept art via its Facebook page. Normally, this wouldn't mean all that much — but with E3 about to begin, it's almost guaranteed that the studio has something up its sleeve.

On the Twitter side of things, there's nothing much yet: the official Guerrilla Games account is live, but the studio hasn't published anything. The account is following a number of its staff members, lending to its credibility, but the only thing that's really suspicious about the account's creation is its timing.

The piece of concept art does however hold a few clues about what fans could see in the future. The image in question was just posted to the studio's official Facebook page.

There was no caption or information posted along with the picture. In any case, it's incredibly similar to the Berlin Wall-esque structure from Killzone Shadow Fall. Is it just a piece of old concept art, or is Guerrilla getting ready to announce a sequel? It's certainly starting to look like the latter...

Of course, there's always the chance that Guerrilla isn't planning a return to the Killzone universe at all: rumors began circulating late last year that the studio was working on a new IP. Almost nothing is known about this 'Horizon' project, and Guerrilla Games hasn't even confirmed its existence. Still, it's not all that hard to imagine one of Sony's biggest developers revealing a huge new IP at this year's E3.

At this point, there's no telling what Guerrilla Games is up to. There's even a chance that it's all just convenient timing, and that the studio doesn't actually have anything planned for this year's E3.

One way or another, fans will find out what the studio is up to soon — Sony's E3 press conference is scheduled to begin Monday, June 15 at 9 p.m. ET.

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