After all, the creator didn't want to be an professinal full-time animator, he just wanted to animate three minutes.
The original author chose those assets and that background, other people made those assets on the first place and had to take a ton of tiny creative choices that changed the final thing and help transmit ideas and feelings (of uncanniness, vulgarity, surrealism, whatever).
Anyone can tell the difference between one and the other.
Maybe I'm wrong but I would say that the slop feeling of the original version was a deliberate decision and part of its charm. That kind of video and voices were a meme back then, IIRC.
None of that is what an Xtranormal auto-puppet show is about.
Pretty much exactly what you see in that video.
“No it was always slop!!!! Nyeh!”
I don't think it is, actually? "Friend-slop" is a super-popular genre of video game right now (for example, indie smash-hit PEAK), typically characterised by low-friction co-op experiences with a low-fi and/or kit-bashed aesthetic
It’s requires a good base group of friends that you will have fun with already, and the design for the game is “slop” / cheap / lazy in that regard. But not necessarily bad.