At first i thought WTF am I looking at? But actually they are quite beautiful in an abstract sort of way.

can the process generate hi-res images?

Seconded! I'd love to have some in really high res (I dunno what for, but I'd love to take a closer look). However, even medium res would be really cool, IMO the generated pictures just a tad too low resolution to appreciate carefully.

Is it a compute/processing power thing? Does it take a lot more time to generate an image at say 5x resolution?

Also what I wondered about, quite a few of the images seem to have a sort of "canvas" like texture on them. Any idea why that is? Would a lot of the source images have canvas textures? Is it an artifact of the algorithm? It kinda feels like a highpass (edge enhance) filter as well. Or maybe they're just JPG artifacts?

the artifacts are explained in detail here

http://distill.pub/2016/deconv-checkerboard/

more compute will enable higher resolutions and less artifacts, but it means training a bigger GAN