Interesting concept. Took me a while to get it but it has potential. I really like the chill atmosphere and art (the music probably had time to loop more than 10 times over while I was playing but it never annoyed me, which says a lot).
I feel like the tutorial is a bit too long though. And the game gets difficult way too fast. At least for me^^ I stopped after completing "Case 1 : Red Harrings" by the skin of my teeth with just 1 "time" unit left after 6 or 7 attempts. I don't know if I was unlucky with all those "Red Herring" items or if I just suck...
To be fair, this kind of strategy / puzzle game isn't really my thing to begin with. So I would wait to see what others think before making major changes to difficulty^^
Also, a few minor things :
- The writing speed for the dialog feels too slow (I know you can get the whole text instantly by clicking though). I would multiply it by something like 1.5 or 2.
- You have 2 fullscreen buttons. I think you should keep the one from Unity and remove the one added by itch.io that never works well (it's in the edit game page, the option : "Fullscreen button — Add a button to the bottom right corner of your embed to make it fullscreen").
At least, that's how I handle it for my webGL games :)
- A custom mouse cursor would add a lot to the style of the game I think. Something thematics like a pen or magnifying glass maybe ?
Anyway, great entry overall, good job :)