EDIT: 5.2 GIGS?? COME ON MAN, IT'S JUST CHESS. I WANT MANMADE HORRORS BEYOND MY COMPREHENSION RIGHT NOW, DAMN IT, NOT AN HOUR FROM NOW
I always kinda wonder where you ppl live that downloading 5.2 GB is such a big problem even with my shitty countryside backwater town connection it's a matter of a few minutes and not hours. UE4/5 is a commercial 3D game engine one of the most advanced in the world atm actually and not a 20 year old freeware 2D VN engine like Ren'Py.
Shaders, Textures and other assets all take a lot of space in modern 3D engines to look good, technology has advanced and 5.2 GB is actually less then some switch or phone games take these days not to mention console or PC games.