ironically, the shader was the easiest thing too add, idk how you would do it in unity but i think is the same process as in godot. basically what i do is in the screen settings for the project, i stretch the resolution, setting the screen to viewport mode i set the aspect ratio to "keep" mode, set the scale to a number between 2 and 4, and set the scale mode to fractional. I also disable the v-sync.
Also thank you for your advice, i shall be making some progress soon, and also good look to you and hopefully to your future proyects!