How can I achieve pixel perfect shadows in 3D

I'm working on a 3D game that has a pixel effect applied to it as I'm trying to achieve a similar look to the game A Short Hike . I currently have this pixelated effect working by using the Pixel Perfect Camera component added to my camera but the shadows casted by my game objects have some sort of anti aliasing on which is causing my shadows to appear really blurry with this pixel effect on.

I do have AA turned off in my project settings and I also have my shadows set to hard shadows. I've doing all the possible tweaking in Project Settings > Shadow Quality with no luck. I've attached a screenshot of how my shadows looks right now with my pixel effect turned on for clarification.

Does anyone know how I could go about getting crisp pixel perfect shadows? I'm looking to achieve the same level of crispness that you can see on the capsule. That shading is achieved using a cel shader.