Hey, I recently discovered this problem, too.
Take a look at this example:
https://github.com/adambiser/ascension/blob/master/onedir.spec
This line in particular:
hookspath=['_pyinstaller'],
That points to a folder where I keep my hooks and I made one for appgamekit:
https://github.com/adambiser/ascension/blob/master/_pyinstaller/hook-appgamekit.py
(file name is important!)
That hook:
1) Makes appgamekit available for import,
2) Adds the "media" folder and Plugins folder (if available) to the dist folder
3) Also adds "icon.ico" if available
Essentially, add and use that hook file and it should include everything you need for you.
EDIT:
Also, for AppGameKit for Python problems, it would be better to post at https://fascimania.itch.io/appgamekit-for-python
The TGC forum doesn't email notify me for some reason even though I have it set up to do so.