When Alan Willard walks the audience through the demoâ€”complete with armored demon, dancing sparks, and rolling balls of lightâ€”the room falls still. Then the twist: Willard reveals that both the cinematic scene and the following tech demo havenâ€™t been running off a game file but in real time from within UE4′s game editor. Itâ€™s like finding out that the actors on TV are actually tiny people living inside your set. It also helps him show that changes can be made to the gameâ€™s design and code, recompiled and executed nearly instantlyâ€”a technical feat that has been simply unheard-of in game development. And just like that, the silence in the room becomes reverent. The videogame industry has changed.