you can use this class to give pygame a shader to render screen. it is easy to use.

I will add tutorial later I have free time.

it's easy to use. I had put example file in it. You can experiment with it and try something new.

1. replace your display variable with a Surface. and blit everything you want to show on that Surface.
2. display set mode with OPENGL and DOUBLEBUF flag.
3. import my shader class. And init a new shader for your game. Remember to pass your display Surface to init it.
4. Replace all display.update with your new shader render function.

Enjoy crt shader in your game.