As someone with a lot of experience playing old games, I've realized that two types of obscure games exist: the type which were never recognized, and complete garbage that should never have been created. I was really hoping that this game would be the former, but it's the latter. (This is why I'm never playing a free VN ever again, by the way.)
I first encountered Mukou no Yume on a VNDB random title binge I was doing. The game looked interesting, and it had an English translation, so I downloaded the torrent file and loaded it up in Deluge. Of course, I've got zero peers. Looking back on it, this was the first red flag.
But back then, I figured that it was an obscure title, so I just found a mirror online and downloaded it.
The second red flag was the title screen music. I've heard the default Windows GM soundfont enough times to recognize it anywhere, and it's generally not an indicator of quality. On the other hand, a lot of older visual novels used MIDI files for their soundtrack because space was much more limited than nowadays, so this isn't necessarily bad on its own.
As far as I know, the soundtrack for this game was taken from an online MIDI library. I'm not entirely sure, but it seems to be the simplest answer, and I honestly don't want to spend any longer looking this stuff up than I absolutely have to. Loading the MIDI files into the Arachno soundfont actually creates generally listenable results, so I recommend it if you absolutely need to play this game and don't want to suffer through default MIDI hell.
I'll admit it, one of the main draws for this game is its art. It's by far the best part of the game, and deserving of a far better scenario than this one. At one or two points, I could've sworn the art was ripped from somewhere else, for just how unfitting the script is. I'd honestly play through an entire game with this type of art.
So far, with everything I've talked about, Mukou no Yume looks outright decent, if not good.
Unfortunately, it all goes to crap as soon as we start talking about the story.
First things first: this game is SHORT. I beat it in around 10-15 minutes.
Now, there are good games that are this short. But I'd like you to examine this chart from VNStat:
Longer games are usually higher rated on VNDB. There are a lot of reasons for this, but suffice it to say that things are not looking up for shorter VNs such as this one.
The story of Mukou no Yume is impossible to explain without giving spoilers, due to the length, so...
A miko commits suicide for unclear reasons, her sister joining her soon after. A fish man is sent to find the girls by their mother, he finds them, then the mother comes down and reunites with her daughters. This is followed by an ending scene where the main character addresses the player for summoning her, then the game ends.
There's nothing more to the story than that. The prose, or at least the translation, is sloppy at best and cheesy at worst. Generally, even in the worst translation, some of the original text comes through. In the case of this game, I can't tell whether it wants to be taken seriously or lightly. On one hand, the miko's sister is heavily toted as comic relief, but on the other she kills herself just to see her sister again.
The ending...oh boy. It just stops in the middle, without ever climaxing or resolving. The story builds up to literally nothing.
In the end, I can't recommend Mukou no Yume to anyone. It's one of the worst games I've ever played, and the presentation can't save the god-awful story.
Don't play this. Please.