Fortnite is PC exclusive, first to utilize Unreal Engine 4 

Today at San Diego Comic-Con, Epic Games revealed the first look at its co-op sandbox survival game, Fortnite, which will be exclusive to PC and the first game to utilize Unreal Engine 4.

During its Comic Con panel, Epic announced the game will release in 2013, allowing players to "explore, forage, collaborate and build by day in their own dynamic and expanding world."

At night, they’ll have to work together to defend their fortress "from the forces of darkness."

Attendees at the panel also received a first look at Fortnite’s building system, which is designed so that "players can use scavenged materials to quickly build and renovate structures of varying materials and complexity."

Over on Polygon, the site reports that during the panel and presentation, producer Tanya Jessen told attendees building is the "core of the game," as everything a player finds will allow them to "build and improve," their structures.

Players can build and edit the walls of their fortification using a 3x3 grid, and even add stairs, windows, doors and rooftops. If you want to rebuild a wall, just use an axe and a sledgehammer to tear it down and rebuild. Players can also reclaim the materials used to build it.

The demonstration also showed various ways to upgrade weapons, the crossbow being one such example, as it can be outfitted with explosives and electric shocks.

Design director Cliff Bleszinski, also part of the panel, said the game was designed exclusively for PC, and while it originally was a more traditional, post-apocalyptic game, the team found the aesthetic to be too "depressing."

Bleszinski has since clarified on Twitter that Epic hasn't "ruled out the possibility of other platforms later."

Bleszinski and Jessen both hinted the game would continue evolve after release, with updates possibly changing gameplay mechanics.

Screenshots are below.