Thank you so much! The effect is known as Dithering, you should be able to find tutorials online about it! I was actually inspired by the game "Return of the Obra Dinn" to use it. If you're interested in the technicalities, I did this specific effect in Unity's URP like this:
1. Make the scene black and white with a Global Volume
2. Make a Dither shader + material with Shader Graph
3. Make a Blit Render Feature to render the visual output using the Dither material
4. Tweak Fog and Ambient Lighting in the Lighting settings to reduce vision
Hope this helps, and thanks again!