Steins;Gate related anime

So, I watched Steins;Gate and I loved it. One of the best shows I've seen. Anyways, there are these two related anime listed as having "same setting", namely "Chaos;Head" and "Robotics;Notes". Also I noticed they both have rather low ratings.

My question here is: What exactly is the relation between these animes? The plot summaries given here seem to have nothing in common, the only similarity I see is in the style of their names, so how exactly do they have a "same setting"? And also, why the low ratings? What makes them so bad? I'm asking because, like stated above, I loved Steins;Gate and would like to know if these other two are worth my time.

All of C;H, R;N and S;G are adaptations of visual novels. The most important point is that the visual novels have a shared setting and the anime consequentially also do, and the same goes for a couple of major themes. That's why they have a same setting relation. That's it; they're otherwise unrelated.

As for why S;G is highly rated and the other two are not, I know that C;H is a bad adaptation of its VN, whereas S;G is a good adaptation; I don't know about R;N. The S;G VN is said to be very good, too, whereas the other two VNs are said to be good but inferior to S;G.

TL;DR: you probably don't want to watch the anime. If you're into VNs, you may or may not want to play the VNs. If you prefer anime, then look for better ones.

Hinoe said it really well- they technically have the same setting but are otherwise completely unrelated.

To break it down simply (based on my opinion):

Chaos;Head - Good source material, terrible adaptation
Steins;Gate - Great source material, great adaptation
Robotics;Notes - Mediocre source material, bad adaptation

I wouldn't recommend either of the other titles just because you liked Steins;Gate, it's an aberration so far, but you can read the C;H VN if you're bored enough. We'll see how their next title goes.

You didn't ask for recommendations, but I noticed you haven't watched any of the Monogatari series titles, or Angel Beats, so you may want to check them out. There really aren't any good similar titles to Steins;Gate around, so general recommendations (based on your ratings and apparent preferences) are really all I can manage here.

Ah, I see. Thanks.

I watched the first two episodes of Bakemonogatari back when it was new, but didn't really get into it. Perhaps I'll give it another chance.

The best recommendation I can give is Noein. It's a little old but the story is great

noein got nothing on s;g. it's slow and the sci-fi part of noein is far less plausible and/or interesting than steins;gate. it's not a terrible show, but it's a far cry from s;g, imo.

What about Occultic;Nine? Does that fit in somewhere?