How Days Gone creators built the horde of zombie-like creatures in their E3 demo

My favorite demo from the Electronic Entertainment Expo (E3) was the Days Gone gameplay demo at the close of the Sony press conference. I saw it again later in a small group session with the developers from Bend Studio. Sure, it was yet another post-apocalypse game, but this one stood out above the rest.

The demo worked well because it felt like it was a scripted scene featuring lead character Deacon St. John as he tried to battle on the run with a horde of zombie-like creatures, dubbed Freakers, in the open world of an abandoned sawmill. The demo had pulse-pounding music that got faster as the intensity increased. Deacon kept finding ways to evade the horde in the nick of time, and the demo included cinematic moments in between the action, such as when he escaped into a garage to catch his breath. Slowly, Deacon ran out options, and he became trapped.