itch.io

Unfortunately right now the only option is to turn down the sound effect slider. This is a good suggestion though, so I'll try to get a fix in for this soon

There is now an option, see my other response.

Under preferences, then audio, there's now an option called "menu effect volume" that controls only the clicking UI sound. This has now been added to the PC demo, web demo, and Early Access. It's still missing from the Android demo, but will be updated soon.

Edit: The Android demo now has this option, too.