Full Disclosure: I am a credited beta tester for this game.
Compared to Zoo-pocalypse, Message in a Melody is more like your traditional Hosted Games title, with a fairly substantial word count (150k), character creation, stats and romances. Still, the Sci-fi genre isn't exactly popular with the Hosted Games crowd, and Message in a Melody is more the 'academic' type of Sci-fi game rather than the 'adventure' type. I'm guessing this is one of the reasons it hasn't done well with that crowd. Still, if this type of sci-fi is the one for you, I do think Message in a Melody could be a pretty strong title.
First, let's talk about this game's signature feature - the ability to unlock music. Well, how this works is that at different points in the game, you can unlock songs, which are essentially links to MVs on external sites like youtube. Unfortunately, I feel that this idea was much better on paper than in the actual game. Due to issues with clicking hyperlinks in game, these links are provided as full URLs which you can copy/paste on the mobile version. Also, even if you're playing on wifi or with unlimited cellular data, moving to another website from the omnibus to hear the music just feels really clunky on mobile platforms. Even on desktop platforms, it also feels immersion breaking to jump to a youtube page just to hear the music. I appreciate the attempt at innovation, but this felt like a huge miss.
The setting and story is pretty well written, and while some writers tend to ramble, I felt that the amount of prose used here was just right. There are also optional modes for full stat transparency, which is a big plus in my book. You play as a member of a race of aliens, out to destroy the human race, until something musical just seems to change your mind. You also have the option to romance some other alien characters in the game, but none of the ROs really stood out, and this didn't feel like a big part of the game anyway.
Given the choice of genre and style, this game was never likely to be a hit with the HG crowd. The external music link system also felt a lot like an experiment which went very wrong. Still, if the more academic type of Sci-fi is your thing, there can be a lot to like here.