itch.io

Seems fine in the online sandbox. (Chrome 79.0.3945.117)

I don't need a refund; This seems to work fine on my other machines (Windows and Linux) and my Mac is supposed to be for work anyway. :-)

After a little more investigation, it doesn't appear to be a problem of hitbox size, but there is definitely something going on that makes me have to try clicking at least 3-5 times before an action is taken. It may be sensitive to click, drag (deliberate or inadvertent drag), and release timing or something, but it makes it very difficult and almost unusable on this platform. 

Ah, I'm sorry, that was a typo. I meant "hitbox," (https://en.wikipedia.org/wiki/Collision_detection#Hitbox) the size of the button that would actually respond to clicks. Even when a button has an area of, say, 20x20 pixels, it would not respond to clicks unless the mouse pointer was exactly on a certain single pixel in the middle of the button.

I am running this on Catalina (10.15.2) but the hibox for clicking on buttons and placing wires is impossibly small, perhaps only one pixel.