Really enjoyed my time with this one. It's short, but I think that works in its favour by letting the game say everything it wants to without stretching things out unnecessarily, and I appreciate the way that it leaves certain things unsaid so the player can read between the lines. The scene with the coach already got mentioned by someone else, but I definitely agree that it's a good example of what works best about this VN: we learn not only that Ken isn't just blowing hot air about the coach being less of a jerk than he acts, but also get an idea of *why* he acts the way he does at the same time.
If I have any major criticisms, it's that as much as I appreciate the VN not over-explaining certain things I do feel like the "bad" endings feel somewhat lackluster as a result of being under-explained. I'm guessing the idea is that the other rat embodies Eddie's personal insecurities in some ways (they seem to have mental health issues going on so I think it's a hallucination?) but it all feels just a little TOO abrupt. In some ways this works (the sudden-ness of it gives them a nice contrast to the much more "lingering" feel of the 3rd ending) but unfortunately I could also see it leaving people feeling a little confused and not necessarily in a way that feels good or intentional.
Also, if I have one suggestion: this is one project that I think would've benefited from using the 'NVL' mode over the default 'ADV' dialogue mode for Ren'Py, partly because it gives the writing (the key part of the VN imo) a bit more space to breathe but also because during the scene with the rat in the coffee ending the default text box covers that part of the image, while using NVL mode would've put the text in the right position to draw the reader's eye towards it instead.
Overall I think you should be proud of what you've made here! I hope you go on to make more projects like this, with a bit more experience I think you have the potential make something great in future.