Since this says new, I'm not sure if this is the same.. but related (to the domain, and the commit history suggests it's the same owner):

Requesting Funding for 90s.dev (86 points, 6 months ago, 64 comments) https://news.ycombinator.com/item?id=44711940

Show HN: 90s.dev – Game maker that runs on the web (352 points, 8 months ago, 113 comments) https://news.ycombinator.com/item?id=44042371

(Looks like https://github.com/sdegutis no longer posts/comments under @90s_dev @9d)

> But there are a growing number of people who are discontent, among both software engineers and UI/UX experts and enthusiasts. Who long for the traditional UIs of Windows or Mac OS, pre XP & X. Who want to pass the love of the 90s aesthetic on to all posterity. Who wish for an alternate timeline where the 90s reigned supreme. Who want to keep pushing the envelope to see what we can make.

(looking at my machines which run Mate and XFCE) What are you talking about? My current UIs are pretty similar to old-style Windows - similar colors, task bars, distinctive buttons with borders. Look at theme list - a Windows 2000 user would love many of those [0]. And all the improvements are either under-the-hood, or very beneficial (like multiple desktops or search in start menu)

https://www.mate-look.org/browse?cat=125&page=2&ord=rating