If one was to remove the entire 'games' directory from /.rockbox/rocks/ on the Clip+, you would save 857.7kB*.
This translates to (if I can math-ify the numbers correctly in my head) a grand total of 2.7 seconds of MP3 @ 320 CBR. Which in turn translates to "...why would you even bother?".
Perhaps there's some ulterior motive here that we're not yet privy to, but presently - with the information given - it seems like a complete waste of time and effort.
If you are not wanting to use the plugins at all (I realize I'm taking a giant speculative leap here), you could just
customize the main menu and remove the 'Plugins' main menu item completely.
[Saint]
* Numbers given are for the current (as of this writing) SanDisk Sansa Clip+ development build - version: 55f1d94-150224.