Images jumping around in Safari

Question

When I play games on my Intel iMac, images will randomly get larger and smaller on the display. Plus I can click on an item in a game several times before the mouse will respond. This doesn't seem to happen anywhere but games in safari. What would be causing that?

Answer 1

Go step by step and test.
1. Delete Caches.db
    Close all windows and quit all applications.
    Hold "option" key down and click "Go" menu in the Finder menu bar.
    Select "Library" from the dropdown.
    Library > Caches > com.apple.Safari > Caches.db
    Right click the Caches.db file and select "Move To Trash.
    Close windows and relaunch Safari.
2. Empty Caches
    Safari > Preference > Advanced
    Checkmark the box for "Show Develop menu in menu bar".
    Develop menu will appear in the Safari menu bar.
    Click Develop and select "Empty Caches" from the dropdown.
3. Delete Cookies
    Safari > Preferences > Privacy > Cookies and other website data:
    Click “Remove All Website Data”.
4. Safari > Preferences > Extensions
    Turn off Extensions if any and launch Safari again to test.
    Turn on those one by one and test.
5. Delete Safari .plist file.
   Quit all applications. Click on an empty spot on the desktop to activate Finder.
   Hold the “Option” key down and click the "Go" menu in the Finder menu bar.
   Select “Library” from the drop down.
   Library > Preferences >  com.apple.Safari.plist
   Right click it and select  "Move  to Trash".  Close Finder window.
   Please don’t empty the Trash.
   Restart. Launch Safari.
  Test Safari.
   If this doesn’t help;
  Put back the com.apple.Safari.plist
   Right click the Trash icon in the Dock and select “Open”
   Right click on the com.apple.Safari.plist and select “Put Back”.