One of the best ways that I know to speed up the game (and your computer) is to remove cookies that from web sites that you don't use regularly. Also, if you are sure that you don't want that cookie, usually you can set your web browser so the cookie never gets allowed.. Check you web browser's help section on how to do this.

Also, clear your cache that's in your web browser.

Defragmenting your computer can also speed up your computer since it will take less time to load files that are defragmented. Almost every time you load or run a file will cause it to become fragmented.

Another way is to only have the game window open and maybe a text editor. Don't open other browser windows as these are checked every so often if they are open and this will take time away from your game window.

The only setting that I know of that will speed up the game is to reduce the amount of time that your battle animation takes. Unless you insist on seeing the animation in all its glory, this setting will dramatically speed up all fight scenes if you set it to reduce the amount of time that your battle animation takes.