Technical problems :
Sometimes, some narration texts have no sense together, missing information, or shown in the wrong order which is sometimes confusing in Mer's route (and I don't mean just at the moment when that was done on purpose as he recounted his story to Charming).
Plot and characters related problems :
Warning : huge potential spoilers
On Mer's route, both endings have Charming act like a selfish and deluded sociopath. None serve a sense of completion regarding what 'Mer' did, and would certainly keep doing doing, had he been let free after all of this. In fact, I don't think Charming's character remains coherent for being still in love with a man she barely knows : because, the only things she knows for sure are mostly creepy. And too few to decide to trust such a person, even for political reason. It kind of clash with how intelligent and independent she was all the way until Mer's endings. Least she would be content to be half a political puppet the rest of her life. Which kind of is the first ending. Regarding justice, I had been somewhat shocked because I had expected Charming and her childhood friend to transfer 'Mer' to another body, because him keeping that one felt wrong after all of this. Though the worst thing in my opinion is how Charming just decide to trust him without retribution and even love him unconditionally. Because in that situation it's completely irresponsible.
Very pretty sprites with very detailed eyes, a tight plot with very interesting characters, including Charming. The surprises in the plot were grand! So moving and dramatic that I know I won't forget them soon.
Overall, the writing is excellent. (And very creepy in both of Mer's routes). The music is okay. My favorite was Mer's. The CGI are...well, passable.
Plot and characters related strengths:
Zel's both routes end in a very satisfying way for both Charming, Zel and the player (...Satisfying. Yeah. As long as the type of Zel doesn't makes them drool too much.) Satisfying even for Charming's country, Lunar Kingdom, as well. I only would have wished for, well, further snuggling? ^^ (I would certainly not mind a sequel.) Also, I didn't miss the light yandere vibe in Zel's first ending. Not exactly necessary but very welcome still.
I haven't played Snow's route and don't know if I will. He didn't inspire me anything so far.
I though there would be an unlockable fourth route with Charming's half fairy childhood friend. (But by the end of Zel's routes, I was too busy sighing giddily to be disappointed. ^^)
It might be necessary to warn players that this game is a very realistic one, so young girls can't be fooled by Charming's pigtails and gloating pink stuff. Really now. Both of Mer's route can be very depressing.
I'll buy the game because of how well thought and clever the beginning of Mer's route was.
End of the spoilers.
I'll keep and maybe replay the game for everything Zel.