I wanted to use a CRT shader to enhance the "retro" feel of my game. I found a free CRT shader for Godot, integrated it, dialed it down a bit so it didn't interfere with visual clarity too much... sadly, it didn't work properly in the web version.
Then, I considered adding the shader to the Windows version but remove it from the web version, but ultimately I decided to keep things simple and cut it entirely. Seems to have been the right choice - almost everybody played the web version only, I have exactly five downloads for the Windows version.
My lesson here is that web is king on itch.io and in future game jams, I'll most likely focus on that platform exclusively. It also shows that time constraints aren't the only constraints.