Just curious, how does one achieve these very accurate "PS1" visuals. Is there a checklist to follow? I've been always curious about it and interested.
We used a combination of the URP (Universal Render Pipeline) and a third party shader.
You can download URP from the Unity Package Manager.
Here is the third party Shader: URP-PSX by Kodrin
URP is used to get the fancy graphics stuff and the Shader is what makes everything look "retroish".
After importing both to your project, you will need to set up Post Processing, there are several tutorials
around the internet on how to do it, i would personally recommned you to search for "Brackey's" tutorials on youtube.
An (maybe) easier alternative, is getting the PSX shader on the Unity Store: PSX Effects.
Unfortunately, he is not compatible with URP, so you would need to know a bit about Shaders in order to make it compatible and without Post Processing you can't get fancy graphics.