You're right, that's exactly the error I see in the log.
WARNING: Shader Unsupported: 'Hidden/BilateralBlur' - Pass '' has no vertex shader
ERROR: Shader Shader is not supported on this GPU (none of subshaders/fallbacks are suitable)WARNING: Shader Unsupported: 'Hidden/BilateralBlur' - Setting to default shader.
My Laptop's Intel HD 3000 graphics are a few years old, true, and it's by no means a gaming machine (below 1% in the Steam Hardware Survey), but so far, yours is the only game on itch that I've had problems with.