A car screeches through busy downtown streets. Controlling a character who sits in the passenger seat, I look behind me and see a host of pursuing vehicles, their occupants climbing onto bonnets to leap in my direction with hostile intent. I take aim with a pistol, and a circular targeting pip flags up exactly when I should pump the trigger on my PS5 remote to blow out tyres and shoot the besuited enemies. The roof of the car I’m in is torn off during this combat, and now I must also contend with a helicopter launching a hail of rockets toward me. Upgrading to a larger weapon, I indiscriminately spray bullets everywhere in sight. The result is an immense explosion which seems to take out all adversaries and draw a line under this action sequence and section of gameplay.

At this point an onscreen logo – Unreal Engine 5 – comes and goes, and after this I float above the same city in which combat just took place (seemingly now clear of the explosions and rubble I so recently generated). Prompts invite me to ‘Toggle Mass AI Visualization’, ‘Toggle Day/Night’, or ‘Toggle Nanite Visualization’, while accompanying text states seemingly related concurrent information about ‘automatic open world streaming’, ‘dynamic global illumination and reflections’, ‘rule based object placement’, ‘particle system’, ‘virtualized geometry’, ‘procedural audio generation’, and more. Pressing x on the controller indeed toggles these values, making traffic appear and disappear, altering the time of the world from midday brightness to night-time halogen glow, or even rendering the entire, extremely verisimilitudinous world into a fractal, primary-coloured cavalcade of tes-sellated triangles (Figures C1a–b). After this aerial sweep, I am plunged back to street-level, where I control a character who can walk, run, and drive through this Western metropolis. No longer pursued by agents, possible activities to undertake are suggested by map markers (if I reach them I will gain access to more toggling options), but instrumental task completion does not seem to be the primary purpose of this world. Rather, these streets seem to be about wandering and languid aesthetic appreciation – I am invited to be awed at the size of this map, the realism of the physics, the scale of the AI, the quality of the audio, and so on.