Poor Es. As someone who's struggled at length in the past with intrusive thoughts, I was very moved watching him fight so desperately against them (as well as against the guilt and shame that so very often go hand-in-hand with them). I wanted very badly to reach through the screen and grab him by the shoulders, saying, "YOU ARE NOT YOUR THOUGHTS!!!"
And that's something I feel this VN communicates very well: It doesn't matter how insistent or gruesome your intrusive thoughts may be; they do not define you or make you who you are, nor does having them automatically mean you're some kind of dangerous monster.
Take that together with all of the other strong points here—the visual presentation, the atmosphere, the simple yet effective world-building and character development—and you end up with quite the powerful VN~
Stellar work (pun intended)!