Cyberix3D - Free Online 3D Game Maker

I want the player to see this blurry mosaic instead of the normal view

The engine doesn't have post processing support currently which is what you need to achieve a blurry mosiac filter over the screen. You can technically try to make or use a transparent mosiac image off google and use it in an "Image" block to display over the screen and turn down the alpha parameter to your desired value.

This might be a stretch but using reshade might be a possibility. If you're unaware, reshade is an external post processing program that injects itself into games, and I believe you might find presets online or even within reshade mosiac filters or similar filters. I've never tried reshade before so I'm not even sure if it'll work.

Sorry if this isn't the answer you're looking for

thanks for the possible solution to the problem, I will definitely try it