Added an alternate download link for minit_racer_itch_noshader.zip that should work as long as you don't change the brightness/darkness settings. Sorry about that!
I'm getting the same Vortex Shader error on the Steam version, are you able to update that version as well?
Edit: https://steamcommunity.com/app/1503530/discussions/0/3106891514121571885/?inside... Turns out this has already been fixed, thank you!