I liked this! I feel like the optimal experience is going through the game once following the "Nice" mood and only then moving onto the other ones. In fact, I'd say it loses most of its purpose otherwise. The art style was good, I enjoyed the atmosphere the 3D rendered backgrounds helped give, and I enjoyed the story and ultimate solution to the mystery.
Most of my complaints come from the minigame department. The first puppet minigame in the "innocent" route (as noted in the other comments) was a bit frustrating; if you pick Takuma, then you're basically going under the assumption that we're talking about the actual murder, in which case there's no point in picking Nao. If you pick Nao, then you're talking about the fire incident, which Takuma has no place being in. The easiest fix is probably just removing both of them and sticking to the key players.
The logic train puzzles I admittedly cheated through. I'd consider simplifying the wheel and just making options that "seem the same but aren't" just merged into one thing. Of course, I say "just" but that'd obviously take a lot of re-tweaking, so I'm really just grateful that the point to cheese through it was there.
The mood system was interesting. I appreciated the way the choice recontextualized Nao as a person. They were a nice touch. That said, some admittedly felt more satisfying than others. I'd maybe suggest tweaking the conditions for the true endings, though; I actually went through all six paths, picking the paths that each mood felt more geared towards, only to realize how the true endings were actually unlocked. In the end, that part felt a bit tedious, even when skipping through everything.
Either way, it was fun! Happy to have come across this and given it a play!