Monstrous Lovers is the kind of Visual Novel I could nitpick to death. Right up front I can tell you that it made me a bit grumpy at times. But let's not get ahead of myself! Let's start at the beginning. Let's start with the reasons why I liked to read this VN anyway, and then, soon enough, we'll get to the nitpicks along the way.
Let's start with...the presentation. The graphics are clean, colorful and give off a light-hearted vibe. The character designs are attractive but non-sexualized and cute (works for me!). Overall really solid. Sometimes the characters are portrayed as bobbleheads, which can look...unsettling. And the characters can look off in the CG graphics. The writing supports the family-friendly vibe of the graphics (if we forget about the opening logo at least). Heck, the VN is so tame that the content of the R18 patch feels grossly out of place. Better to skip it. It's like if sexually explicit fan drawings of Steven Universe characters were edited into one of the show's episodes. For the most part the story remains low-stakes and of the slice-of-life variety, charming and amusing. It's a bureaucrat's gay monster fantasy! More excitement wouldn't have hurt, but I liked the light-heartedness that not just infused the graphics, but also the story. Vincent's route reveals an interesting backstory about our shamelessly flirty vampire. The main story offers well thought-out insights about the bureaucratic treatment the monsters receive and what their mundane issues are. Vince can tell you all about the nasty taste of bottled blood. And Christopher, our protagonist, can give a lecture about the principle of extraterritoriality pertaining to demons and vampires. Those specific details make the game world more believable. I can't speak for the two routes I haven't played, but at least on Vincent's and Ben's route the business about the census doesn't really go anywhere, which is a shame, especially after all the drama about getting the job. At some point the romance breaks of from the main story at the DOI (Department of Integration) and leaves it in the dust. It would have been more satisfying if the two story branches came together in the end.
The four romantic interests are varied types. You get your choice between a teen(?) wolf and a centerian vampire, an invisible man and an android. It's kind of weird that you're able to date the antagonist that is so eager to refuse you a job for no apparent reason. Really hard to get over that!
But I'm getting ahead of myself. I guess it's time then to talk about the biggest gripe I have with this game, the one on the top of my list: the Game Over I just couldn't move past, the one I got over and over ad nauseam (just give me the damn job already, Sebastian!). It really left me wondering where I went wrong with my choices. Who can tell? What's the purpose of the choices anyway? I can take a guess, if I compare my ill-considered choices with the proper ones according to the walkthrough. As far as I have figured out it works like this: if the VN gathers that you're not open enough to the monstrous inhabitants, then you will fail to get the job. How one connects to the other isn't made clear. I could speculate, but nothing I would come up with would be covered by the text of the Visual Novel. This is also unfortunate for another reason. To pick a certain route it's conventionally just as important for a VN reader to show disinterest in characters they don't want to romance than it is to show interest in the character they want to. At least according to my experience with Visual Novels! This break from convention seems rather irritating then, especially since the presentation of the choices seems to suggest that the VN would stay true to those conventions. In the end, having been through a few Game Overs too many, I've decided to play the rest of Monstrous Lovers with a walkthrough at my side. Fun! Ah well. Personally, I prefer if Visual Novels give me a good story no matter what. Before I got fed up with the Game Overs though I had honestly fun with exploring more of the content behind the various choices. There is lots of alternative content, not just a few different lines here or there, but entirely different scenes. And to be fair, the mentioned Game Over is the only one you need to move past, after that the story will play out to the end and deliver either a good or bad ending.

The Spanish voiceover is an excellent addition even when you don't understand the language. It gives the characters an extra dose of life and charm. Too bad then that it stops shortly after the content of the demo is exhausted. The sudden lack of it takes away a chunk of the fun and excitement. Nevertheless, I settled for less and the rest continued to be enjoyable.
Speaking of the sound side of things: The music is generally good, but lacking in variety and quantity. A few tracks you hear too much of, especially the goofy ones that weren't to my taste anyway. And don't just casually drop in Eric Satie for some sad music, game! Sound design is barely there. There's no ambient sound, only the rare sound effect. The sound effects can be off. The knocking on the door sounds more like a nail beaten with a hammer. Often the VN falls entirely silent.
Just as undercooked feels the presence of the town in the story. The story focuses on the romanceable characters so much to the detriment of everything else that the town feels empty. It's underutilized, considering the potential of the premise. What's left to gripe about? How about the typos, grammatical errors, missing and redundant words? There's not a huge amount of them, but definitely unusually many. And why does it say in Ben's R18 scene that they're in Vince's living room when they're obviously in Ben's?
Add that to the rest and the game has a rather unfinished feel. Like it's not everything it could be. Ah well. Still! All in all this is recommended, this flirty, cartoony, cute, light-hearted and mostly (mostly!) relaxed time of ample length.