Generally you should should set your Sprites "Filter Mode" to "Point (no filter)" and "compression" to "none", so they stay sharp and download the "2D Pixel Prefect" Package and add a "pixel perfect camera" component to your camera. Set the reference resolution to 84x48 (or the other way around) and enable upscaling.
There is a bunch of other things you can do and add, but this should get you the minimal requirement for the look.
