So that's how games will look like in 15-20 years, cool I guess.
So basically, the engine sort of works like RT except for rasterization, where instead of rays/pixel it renders polygons/pixel, sounds so logical and so obvious once someone finally sorted it out. Which still, 4K is around 8M pixels, so it should translate into 8M polygons, yet Epic mentioned there are about 20M polygons being rendered in each frame, that's a huge gap/difference, and on top of that the demo ran at 1440p, which is about 3.5M pixels, so the difference is even greater, the engine basically renders 5-6x more polygons than it can actually be displayed, it just shows how much room for improvement there is.
The temporal GI looks nice as well, if that can be rendered on CUs that means more RT power can be left for reflections, shadows etc., which combined could create outstanding results.
Other than that, what a boring demo, it looked exactly like many current-gen open-world walking sims except with better visuals, the animations systems while looking great makes everything even slower than it already is, and there were still forced slowdown sections... I just hope there will be more smaller scale/linear games in the upcoming generation like they were during PS360 times, instead of even bigger, even more boring open-world games.
But like I said, it's just a tech demo like many others before, so I don't expect the actual games to look nowhere near that good, probably next Gears will be the best utilization of the engine, while most 3rd party/indie titles will as always produce average visuals with average performance (30FPS). And by the time we'll get a hardware on which those visuals will be actually possible to pull out new technologies will show up that will take over. And the cycle continues.