Using the new Firefox profiler [0], which isn't quite ready for public consumption yet but already very helpful: 1. Download Firefox Nightly [1] 2. Install th

Using the new Firefox profiler [0], which isn't quite ready for public consumption yet but already very helpful: 1. Download Firefox Nightly [1] 2. Install the profiler addon [2] 3. Play the game 4. Press Cmd+Shift+O to open a profile of the most recent few seconds 5. Wade through the tree until you find nsIDOMHTMLImageElement_SetSrc, which is called by <Anonymous>() @ CompletedEnemies.js:2460. This function contains only one line which assigns to the src property of an image, and that's the line I pasted. [0] https://developer.mozilla.org/en-US/docs/Performance/Profiling_with_the_Built-in_Profiler https://developer.mozilla.org/en-US/docs/Performance/Profili... [1] http://nightly.mozilla.org/ http://nightly.mozilla.org/ [2] https://addons.mozilla.org/en-us/firefox/addon/gecko-profiler/ https://addons.mozilla.org/en-us/firefox/addon/gecko-profile...