There's something to Dimension 404 that slightly appeals to both the geeky and the TV-nostalgic side, thanks to it sticking closely to two obvious inspirations.
First, there is the official inspiration of "The Twilight Zone", the classic, ground-breaking sci-fi/thriller anthology series from the late 1950s and early 1960s. It's fondly remembered today as pioneering in science-fiction with heavy philosophical and social commentary, and has influenced pretty much all sci-fi and thriller films and shows that have come after. For the uninitiated: in this context, "anthology" means that each episode tells a self-contained story. While there are sometimes references and allusions between episodes, or shared characters, they generally offer a completely new plot, cast, and often writing/directing staff for every new episode. It's a format that has, in my opinion very sadly, come out of fashion in recent decades. It's more lucrative for networks to build in overarching plots and cliffhangers, encouraging viewers to tune in week after week for fear of missing important events.
The other, as far as I know not officially mentioned, but still very obvious inspiration is the British series "Black Mirror" created by Charlie Brooker. That series is still running, and pretty highly appreciated by critics and audiences. It sticks to the anthology formula, but handles topics a bit more of-the-day, such as the effects of social media, online dating, or artificial intelligence on people and society.
In fact, Dimension 404 feels so much like Black Mirror that it could be mistaken for its official US adaptation, except for offering different episode plots.
I have to say, though, that I wouldn't rate Black Mirror that highly overall. Anthology series are often hit-and-miss from episode to episode, and Black Mirror just had a few too many misses in my personal opinion. There were some highly memorable episodes that reminded me of the best of The Twilight Zones. Stories that stick with you for years, and randomly pop into your head, triggered by some new real-world headline or discussion. Others, though, felt very gimmicky, and more like the writers were struggling to come up with a controversial plot about some pre-determined topic.
The same goes for Dimension 404. I really do appreciate the geekiness of it all. The cheesy intro as a straight update of the Twilight Zone intro, the hidden occurences of the number "404" in many scenes, and the relatively high production values all make it a pretty bearable watch. However, the stories I've seen so far just feel too stretched out. The ideas are not really clever enough to justify being dragged out over a whole half hour, and they are often quite predictable.
I feel slightly bad giving this show a rating just slightly above average, because it seems to be directly targetting me from two sides. And I commend the creators for having put their heart in it, and having done a lot of things right. It's just the writing itself that doesn't feel up to par. I haven't seen the entire first season yet, and reserve the right to adjust my rating slightly still. But I hope that the show will be successful enough to give its creators the chance to improve it in future episodes.