Snake Rewind: Episode 8 - Visual Glitchcraft

In our final Episode 8 of the Snake Rewind devlog we dive deep into postprocessing effects to give our game a full retro CRT vibe. From scanlines and flicker to distortion and RGB channel splitting, this episode brings raw visual style to the grid.

What We Covered

• Implemented animated scanlines with configurable frequency and opacity
• Added subtle light flicker for a dynamic CRT shimmer
• Applied sine based screen distortion to simulate signal warping
• Built a chromatic aberration shader (chromasep) to split RGB channels

This episode is all about turning the clean pixel grid into something with personality: unstable, glitchy and wonderfully retro.

Design Insights

• Scanlines are a sine modulation on brightness based on fragTexCoord.y
• Flicker is time based and global, modulating brightness subtly
• Distortion uses UV displacement with sine waves for wobbly lines
• Chromasep offsets the red and blue channels using a randomized distortion
• Effects are layered in order: base scene → glow → scanlines → distortion → chromasep

Implementation Highlights

• This episode’s effects all reside in scanline.glsl shader
• Used globalTimer utilizing GetFrameTime() to animate phase and flicker over time
• Used a temporary RenderTexture2D to chain passes cleanly
• Composited the final output directly to the screen

External Resources

• Creating a scanline effect in Shadertoy - initial source for scanline shader, but we built our own thing
• Mini: Chromatic Aberration

Tweak and Expand

• Add background music and sound effects (based on free assets). I will gladly merge your PR if you would like to contribute.
• Clean up the main file and split relevant functionality to specialized header/implementation files
• Extract some parameters from shaders as uniforms and configured them from our main
• Add any other effects you think will make the game look even better!