Yeah. Game makers would make good use of pre-built icons for clickable features that requires buttons.
Developers Pack Green Icons
I have downloaded and uploaded this "Developers Pack Green" icon set only for sharing purposes on this site here. As you can see, I did not create this icon set. This icon set has 90 icons and is 32x32 pixels in size. Read the information from the author below:
This icons pack made by Freeiconsdownload from http://www.freeiconsdownload.com
These icons are free for personal, non-commercial use.
if you wish to these icons for Commercial website, software or commercial project.
You must indicate the icons Author "Icons are from http://www.freeiconsdownload.com in your projects.