This is a screenshot of my latest code with the Shader in effect. It's a bit of a cheat actually as I had to slow it down 10x so I could take a screenshot. Which is a way of saying a static screenshot doesn't really give an idea of how it looks in action, at 60fps with everything moving.
Also the game now uses no art assets: everything is procedurally generated. I don't rule out using art in the final game but for now it's quicker and easier to work in code where I change a few numbers to completely change the look and feel of things.