I see this issue in quite a lot of indie games. The transparency effects for the controls icons are virtually invisible much of the time against light backdrops. A well-contrasted background behind the icons would help with this. At present I can't tell what I'm clicking most of the time because all I see is a vague impression of the button box shapes. This is within the simulations, not the main menu which is fine.

Noted, I'll look into adding a halo around some icons and text