The hit box are too tiny for the mouse. They are also not continuous.
In other words, the control scheme is bad. Please only use rectangles as hit-box. Also, use larger rectangles.
Yes you re 100% right. But I'm using flickgame tool, which is really good to make game quick and without using any code. Each color on page is attached to a link to another page. 16 page total max. You should have look, you might like it : https://www.flickgame.org/